Wonderbirds: Beneath the Abyss

by 8_Bit

Rating: everyone
Tags: Applejack, My Little Pony: Friendship is Magic, Alternate Universe, Rainbow Dash, Other, Science Fiction, Fluttershy, Adventure, Crossover
Length: 16445

When a crisis unfolds at a deep sea laboratory, Equestrial Rescue must face off against unimaginable odds to get everypony out alive.

'Calling Equestrial Rescue, this is Deepsea Echo laboratory currently operating out of the Mareiana Trench. We were hit by some unpredicted seismic activity and in our attempt to evacuate, one of the escape pods malfunctioned. To our best understanding the docking clamps have failed to release fully but the water seal between the doors has breached, so we're trapped inside the pod. The lab is at a depth of six point eight nautical miles and the pod only has an oxygen supply to last us a few hours. Please, Equestrial Rescue if you can hear this message... help us. You're our only hope.'

Crossover with the hit 1960's TV show Thunderbirds, which is the property of the Gerry Anderson Legacy and ITV Studios.

Wonderbirds is a series of standalone, episodic one-shots and shorts, not set in a linear narrative to each other. Though presented as a series of stories, you do not have to have read previous ones to understand the narrative in each one.

Published 2023-02-05 17:20:00 UTC
Last updated 2023-02-18 23:06:54 UTC

I: Calm Seas Overhead

"Uh... say that again, 'One?"

"You heard me, 'Two, it's the Navy. The sun-spangled, rooting shooting Equestrian Navy. I'm circling them now, I can see an aircraft carrier and two destroyers."

Applejack turned back in her seat to look to the bench behind her, where Fluttershy could only glance back with a raised eyebrow and shrug of her wings. "The distress call from Deepsea Echo only came through to Wonderbird Five about fifteen minutes ago," she mused.

"Base from 'One, Base from 'One," Rainbow Dash's voice spoke in both of their earpieces. "This lab, they got military funding or something? Any reason there'd be a fleet of warships above it?"

"Negative, 'One. And I can check with my naval sources, but I don't think there's any exercises planned in that area today," came Twilight Sparkle's voice in reply. "And I've already checked the transponder signals from those ships, they're the real deal."

"But how'd they get there so darn fast?" Applejack asked, tapping her hooves on the control yoke. "That trench is hundreds 'a miles offshore. They could never make trails that fast, they must'a already been sailin' nearby."

"I really hope that's a coincidence," Rainbow Dash replied. "They're trying to hail me, I think they want me to land on their carrier."

"We managed to tick the Navy off yet? 'Ah swear they threatened to shoot me down before."

"Nah, you're thinking of the Marines, 'Two."

"Well if they ain't already plannin' on shootin', ah reckon we best keep 'em on terms that are good and peaceful like."

"Sounds good to me, 'Two, they're directing me to a helipad on the stern. What's your ETA?"

"Not too much longer," Applejack said as she cast an eye over her instruments. "'bout twenty minutes, ah reckon."

"Copy that, I'm gonna see what I can find out down there. Over and out."

Turbulence jostled the ship as Applejack adjusted her course. Specks of green on the blue horizon indicated they'd reached the Mareiana Islands. Only a short flight south-west of Harmony Island, the crescent-shaped archipelago comprised of the summits of a dozen undersea volcanoes. Their flight would take them past the islands, off the starboard side of Wonderbird Two, out to sea off the southernmost tip of the chain.

The shifting of tectonic plates over millions of years had formed a geological wonder, where the Pintocific Plate met the Mareiana Plate and was thrust downwards. Over time this had formed the nearby islands, and the constant shifting accounted for the volcanic activity that was common in the area. Applejack had already been to rescues in the area several times since she joined Equestrial Rescue. She never had a dull visit to Mareiana. She'd evacuated small villages, conducted search and rescue operations, and even redirected the occasional lava flow.

But this time they were bound for the trench far out to sea, and instead it would be Fluttershy taking the reins of the mission. Her aquanaut training had been extensive, Applejack had no doubt, but the Mareiana Trench was seven miles deep. It was another world down there. She couldn't help but be apprehensive. After all, she was responsible for transporting Fluttershy from their base to the danger zone. Almost like if anything went wrong, she'd be partly to blame.

"You'd better get back there and start preparin' her," she said, not taking her eyes off the horizon. "We'll be there soon and we'd best be droppin' you in the water fast, we ain't got the time to waste."

"Are you sure?" Fluttershy asked, rising to her hooves. "You don't want to hear from Rainbow Dash first?"

"Darn right 'ah don't! Get ourselves all tied up with bureaucracy? Nuh-uh, way 'ah see it is we're here to do a job, save some ponies in trouble. If'n the Navy wanna take issue, they can do so when we're back in the dry."

"Fine by me," Fluttershy said, stretching her wings as she headed for the door. "I'll be on comms still, in case she does call in."

"Oh she'll be al'rite," Applejack laughed. "Bunch'a overcompensated sailors with a fondness for big guns, they won't know what hit 'em."

Sunshine bore down on the deck of the ESS Seaquestria, the light breeze doing nothing to dispel the incredible tropical heat. Already a cacophony of jet engines and mechanical noises, the deck of the immense carrier now came alive with the sound of thundering hooves as many of the assembled crew migrated to the stern helipad. Everypony who wasn’t pre-occupied was keen to get a good look. The deck crew was only able to watch their peers assembling, all of them in hopes of a close up view of a legendary Wonderbird. They were all in awe of the new arrival. It stood out, that much was certain.

Wonderbird One’s engines whined down to silence as Rainbow Dash ran through a quick landing checklist, paying no mind to the gathering crowd outside the polarised glass of the cockpit. The navy-blue rocket dwarfed the various jets lined up on the deck, and had barely fit onto the available space at the stern of the carrier. It was Dash's skill for landing on a bit that had brought it down safely. Satisfied that her craft was secure and wouldn’t slide around or take off of its own accord, she donned a full face helmet and rose from her seat.

Given her years of active service in the Wonderbolts, she was a well known face. Her mane was even more distinctive. Measures had to be taken for security. Their uniforms were full body, covering them from neck to hoof. They even had sleeves to accommodate for their tails. Each uniform was pale blue, with accents running up their sleeves colour coded to each of their respective Wonderbird. Rainbow Dash’s uniform, in this case, had accents of a dark blue. Her helmet was identically coloured, and had a visor of solid black. It looked like a strange in-between of an astronaut helmet and a fighter pilot helmet, but it offered her unimpeded peripheral vision and was light as a feather.

The uniforms had been a long collaboration between Twilight Sparkle and Rarity. The fabric was light, waterproof and almost unbreakable. It would keep its wearer warm in cold weather, and cool in warm weather. Integrated bio-circuitry would track their vital signs, and for the most part could compensate for extreme changes in pressure and temperature. The helmets had their own on-board oxygen supply, and when worn would work in tandem with the suit to keep its wearer healthy in all kinds of environments.

Rainbow Dash was grateful for all the work that had gone into her outfit as she stepped off of Wonderbird One’s access ladder and onto the deck of the Seaquestria. Everypony gathered around her looked weather-worn, and there wasn't a single uniform free of sweat patches. All she could feel was a pleasant coolness, like she'd had a sip of a refreshing cider after a long workout. Dash stepped away from her craft towards the crowd, as a pink pegasus mare stepped forward to meet her in the middle. The mare saluted with her wing.

“Equestrial Rescue, it’s good to see you here,” she said. “I’m Captain Jetstream, commanding officer of this ship.”

“Pleasure, Captain,” Dash replied, bringing her hoof to her head with a salute of her own. “Your crew, they always sit and gawk whenever you get a new arrival?”

“Well, your craft alone puts my entire fleet to shame,” Jetstream said with a smirk. She turned to address the crowd. “Alright everypony, back to your stations, we’re on a mission here!”

Distinct groans erupted among the crowd as they turned tail and went back to their various jobs. The vast majority headed back to the ‘island’, the large tower rising from one side of the deck that housed the ship’s bridge and the flight control tower. Everypony else descended through hatches in the deck down into the lower levels of the ship. The dispersing crowd gave way for another pony, a pegasus stallion with a navy blue coat to step forward.

“This is North Star,” Jetstream explained as the new arrival also offered Dash a salute. “Air Officer, runs the flight deck.”

“Captain of the ship, commander of the flight deck. Two highest ranking ponies on board,” Dash said, watching with interest as, at that moment, a jet took flight from the bow of ship. Its engines screamed and faded as it chased the horizon. “So I take it you two are the ones to talk to for an explanation on what the hay this ship is doing here?”

Lights flickered on as Fluttershy stepped into the cavernous space, the door sealing itself behind her with a hiss. Wonderbird Two was a huge machine, designed in two parts. The primary superstructure contained the cockpit, wings and propulsion. It functioned as a frame, surrounding a central system of interchangeable cargo containers. These containers were often referred to by the infomal nickname of 'pods'. Each numbered pod contained different rescue equipment suited to a different scenario. As part of Wonderbird Two's launch sequence, a line of pods would roll along beneath the ship until the correct one aligned into position for loading. Then when ready, Applejack would lower the entire ship into place around the pod, securing it ready for flight.

For this rescue, Fluttershy found herself inside pod number four. The room juddered in the turbulence as she began her pre-launch inspection by doing a full walkaround. She circled the machine housed in the pod. Her machine. Wonderbird Four, the smallest of the Equestrial Rescue fleet, but by no means any less important. It was, after all, their primary method of underwater rescue.

It was only small by comparison, a yellow submarine the size of a large semi truck cab. A pointed dorsal fin reached upwards towards the ceiling of the pod, bearing the number four on either side. Two more fins of equal length jutted out either side of the craft, like aircraft wings. Once in the water these would lower into their operating position at equal distances from each other. When configured during operation, the machine looked like a three-pointed star with a fat tube at the centre. A tinted glass canopy offered Fluttershy good views in every direction. A glass floor underneath the control seat extended the visibility downwards, and a series of onboard cameras filled every other blind spot.

Fluttershy paced around the submarine, running her hooves across the control surfaces and taking the time to check for cracks in the hull. She checked the water intakes and the thruster exhausts for any loose debris. A display on her wrist-mounted computer told her the main computer on-board the submarine was running its own system checks. It beeped at her when it was ready to check the exterior lights. She watched as powerful halogen spotlights switched themselves on and off at the bow, and red beacons began to flash at the tips of each of the control fins. Her wrist computer beeped again, requesting her approval. Fluttershy tapped at it, confirming that she was happy with her exterior checks, and told it to continue its program.

A gentle hum filled the pod as Fluttershy made her way over to a small storage locker, finishing her circle and grabbing her helmet. Wonderbird Four’s turbines were beginning their start up sequence, a sign that the pre-launch checklist was almost complete. The turbines would only start when the life-support systems checks had cleared, a signal to Fluttershy that it was safe to board. As if on cue the whole room seemed to give a gentle lurch downwards, a very similar feeling to being stood in an elevator as it starts to descend. They had to be on final approach now.

She flicked hair out of her eyes as she pulled the helmet on. In her younger years, her mane had been far longer, often dragging along the floor. But this had been an impossible style to maintain as an operative for Equestrial Rescue. It was a trip hazard, it could be prone to snagging on any obstacles she encountered, and crucially it was too long for her helmet to fit and maintain an airtight seal with her uniform. Fluttershy now wore her mane short, and when off-duty had taken to styling it in a spiky, windswept manner.

“Running through final checks now,” she said as she made her way to the airlock hatch on the side of the submarine. It hissed open as she approached. “Exterior check is good, system checks are green and life support is a-okay. She will be ready for launch in a few minutes.”

“Copy that, ‘Four,” Applejack replied. “'Ah can see the carrier just off in the distance, they sent us some feller in a jet to escort us in, mighty formal of ‘em if you ask me.”

“And ‘One hasn’t called in yet. At least, I haven’t heard her call in anything yet.”

“Me neither, 'ah had a look at the video feed from her helmet, she’s talking to a pair ‘a ponies that mus’ be in charge there. She sure as sugar don’t seem to be under arrest, and they ain’t sending missiles our way so 'ah’m gonna go by the assumption that it ain’t in their plans fer today. And if we ain’t what they’re interested in…”

“They must be going after the crew of the laboratory,” Fluttershy concluded. She sat down in Wonderbird Four’s control seat, tightening her seatbelt as she felt the whole ship bank to the left around her. “Are we there yet?”

“Sure are, jus’ having a circle to see what 'ah can see. Lookin’ like the escape pods that made it out are startin’ to surface, 'ah can see them getting craned onto the carrier.”

“Okay, that’s good.” Fluttershy said, as the console screens flickered into life. The control switches on her overhead panel all glowed with a green backlight. “Systems checks are complete, docking clamps armed for release. All go for pod deployment.”

“Copy that, ‘Four, lemme find you a nice spot fer droppin’ down.”

Fluttershy braced herself again as the bank angle changed, swapping from left to right as Applejack brought Wonderbird Two around into a better position. To launch Wonderbird Four was always a nerve-wracking process. But Fluttershy couldn’t deny that after every launch, she managed to see the fun side of it.

“We are in position for the drop, is the payload ready?” Applejack asked as they levelled off again.

“Releasing the docking clamps now, payload is ready,” Fluttershy confirmed.

”Bombs away, sugarcube.”

Suppressing a squeal, Fluttershy clamped her eyes shut as a great falling sensation came over her. She braced herself against her restraints as she fell for what seemed like an eternity. And then with a great thundering boom it stopped, a complex suspension system in the floor of the pod cushioning the impact for its inhabitants. It was odd being inside the pod when this happened, without any windows there was no visual sign that anything had occurred. The only sign of change was a rhythmic back and forth rocking of the room, in contrast to the constant rumble of Wonderbird Two’s engines.

Then sunlight pierced its way into the pod as the massive door in front of Wonderbird Four began to swing open, lowering itself down to the sea and becoming a ramp. As it opened the view in front of the pod became clearer, and Fluttershy caught of glimpse of Wonderbird Two hovering nearby. It was almost comical to see it flying around without the pod, a massive gaping hole in its belly. Hence Twilight had designed it with plenty of rescue equipment aboard even without the pod. Below it, Fluttershy saw the Seaquestria. From her low position in the water, the aircraft carrier was unfathomably huge. The flight deck sat upon two hulls in a catamaran structure that dwarfed her own submarine. Even Wonderbird Two looked small compared to it. For a moment a thought crossed her mind: what could be so important that the Navy would send a ship this big to a rescue mission? There was something else going on here for sure.

As the pod door dipped into the gentle waves, an orange beacon on the ceiling of the pod began to flash. The door was locked into position. Fluttershy flicked a switch off to one side of her control console, and then felt herself begin to lean forwards. The submarine was sat on a track built into the floor of the pod, which was raising up from the rear to meet with the same angle as the open door. Once locked into place, it would provide a single, constant incline that Wonderbird Four would descend along into the water. A second beacon on the ceiling, a green one, began flashing to confirm that the ramp had aligned and was ready for launch.

“Wonderbird Four is go,” Fluttershy declared as she pushed her control stick forward.

The yellow submarine jolted forward, turbines whining as it made short work of the small distance from pod to water. It hit the surface and, with a whir and a splash, dove beneath the waves.

Rainbow Dash examined the 3D model projected onto the table in front of her. The Deepsea Echo laboratory resembled some kind of insect, interconnected spherical modules lined up one after another, with long spindly legs protruding from every third sphere. The design allowed the lab to walk across difficult terrain on the ocean floor, and navigate around larger obstacles. Each sphere had two small cylindrical protrusions on either side, which Jetstream had explained were the escape pods.

"And there's no chance of remotely manoeuvring the lab into shallower waters?" Dash asked.

North Star shook his head. "Part of the emergency shutdown disables forward movement. That way the structure doesn't walk itself off a cliff while ponies are still evacuating. There's a manual override switch, but that's located in the main control room at the front of the lab. The emergency shutdown would have activated the moment the earthquake hit."

"We've been tracking the lab's movements for a week now," Jetstream explained, glancing out the window at Wonderbird Two hovering nearby, which was lowering a line of cable down into the water. "The reason for that is classified."

"Yeah, classified, you've said that already." Dash said, rolling her eyes to herself, knowing the visor on her helmet kept the action unseen. "Can you tell me when they last surfaced?"

"A month ago, but their operational permit requires them to surface weekly."

"So you're just here chasing them because they missed a rendezvous or two?"

Jetstream narrowed her eyes. "I'd elaborate if I could, but that's part of it, yes."

Glancing around, Rainbow Dash took note of the ponies around her. After landing, Jetstream and North Star had led her up to the ship's bridge. The three of them had watched the arrival of Wonderbird Two, the subsequent pod deployment, and the launching of Wonderbird Four.

"Look, we're here to help," Dash said, looking between Jetstream and North Star. "There are ponies down there who will die if my team decided to pack up and go on home. Danger is part of our job, it's a risk we accept. But if there's something else going on, something that adds another element of danger to this, I think we've earned the right to know what it is."

North Star looked to Jetstream. Her face remained stoic, but her eyes seemed unfocused and distant, her ears folded backwards in a telltale sign of uncertainty. She seemed to be considering Dash's words.

"Let me make a call to my superiors," she said finally. "Wait here for a sec, okay?" She trotted away to a small office at the rear of the bridge, closing the door behind her.

North Star managed a sympathetic smile, then walked away. Rainbow Dash found herself alone at the table still displaying the 3D projection of the lab. She gave a subdued sigh as her tail twitched in agitation.

"'Two, 'Four," she spoke into her microphone. "Gimme an update."

"'Four's descendin' with the tow line right now, sugarcube." Applejack's voice chimed back.

"At safe descent speed, I should see the laboratory in about ten minutes," Fluttershy added.

"Good, just... go careful, 'Four. There's something they're not telling us here." Dash said, starting to pace back and forth.

"I keep thinking the same," came the reply, with a distinct note of concern. "This is a big operation for a simple search and rescue."

"The captain just admitted they've been tailing the lab for a week. Says that the lab's supposed to surface weekly but it's been a month now with no show. I don't like this. The official story here is that they abandoned ship because of an earthquake. That's what the laboratory crew called in, and that's what they're telling me here. I think there's more to the story."

"Is there anything we can do?"

"Not at the moment. The Captain keeps saying that everything is classified, she's making a call to her bosses at the moment to see if she can give us any information that we'd need to know."

"Did she say if they managed to get back in contact with the damaged escape pod? I've been trying to call them but they aren't answering."

"It's all hearsay right now. They think the comms on the trapped pod were damaged in the quake, weakening the signal. But the ascending pods were able to relay it so Wonderbird Five could pick it up. Either their radio died afterwards, or the other pods rose up and out of range. We're just guessing at this point."

"Okay. I'm going to call base, see if they've got a plan for me, tell me if you come up with anything."

"Copy that, 'Four. Good luck," Rainbow Dash said, resting on her haunches as Fluttershy's line went quiet.

"Hey 'One, yer on the bridge, right?" Applejack asked.

"Yeah, why?"

"Go take a peek outside, they're haulin' the last of them escape pods onto the deck now."

Obliging, Rainbow Dash trotted towards an open doorway that led onto a small balcony overlooking the flight deck. Wonderbird Two was still hovering nearby with a long cable lowering from its hull into the water below. As it unspooled, Fluttershy would be manoeuvring Wonderbird Four deeper and deeper with the end of the cable held in the submarine's grappling claw. True to Applejack's statement, the escape pods that had been successfully launched were grouped together to one side of the flight deck. Some ponies were still climbing out of them.

In a normal rescue effort, Rainbow Dash would have expected anypony exiting the pods to be swiftly escorted inside the ship. Medical checkup, warm soup and a blanket, all the usual stuff. So she was surprised to see that a large number of ponies, presumably all of the ones who had successfully evacuated the lab, had been seated in a long line along the deck.

As she leant forward, she watched as a pony climbed out of an escape pod, only to be swiftly shackled by their front hooves and escorted down to the end of the line. There they were forced into a sitting position, where another set of shackles was attached to their rear hooves.

"You seein' this as well, 'One?"

"Yeah I am. Those ponies are under arrest."

Wonderbird Four descended swiftly, one of its retractable claws extended and holding tightly to one end of the cable being unspooled from Wonderbird Two. With a combination of the three point harness keeping her in her seat, and the seat itself mounted on a pivoting arm, the submarine was able to dive at a near vertical angle in relative comfort for Fluttershy. The view outside her window had long since succumbed to the inky blackness of an aquatic world deprived of sunlight, though every now and then a bioluminescent creature zoomed past.

It was primarily her love for animals that had persuaded Fluttershy to accept the role Twilight had chosen for her. The ocean was the home to so many creatures, known and unknown, and her fascination had won out. The chance to observe them in their habitat was too good to pass up. Much of her time off duty was spent cataloguing the flora and fauna in the reefs around Harmony Island, but she'd spent far less time in water this deep.

She shook her head as another distant glow passed by, and turned her attention back to the task at hoof.

"Base from 'Four, I should sight the Deepsea Echo in eight minutes," Fluttershy said, her hooves easing the controls in a gentle swaying motion, ensuring the cable didn't snag on Wonderbird Four's fins. "Do we have a plan?"

"I think we just about do, 'Four," Twilight Sparkle's voice replied, as a screen came to life on Fluttershy's control console. "Can you see the schematic I've sent over to you?"

"Got it," Fluttershy said as her screen showed her a cross section of the lab. She tilted her head slightly as the resemblance of the lab to some kind of crustacean danced across her mind.

"Okay, in short: we can't just pull the malfunctioning escape pod loose, as at that depth we risk compromising the integrity of the hull. Since the laboratory was built in compliance with Pintocific structural regulations, the escape pods use a universal docking seal, compatible with the airlock aboard Wonderbird Four."

"So I can attach to any of the airlocks used by a departed escape pod?"

"Precisely," Twilight exclaimed. "The floatation systems on the pod seem to have malfunctioned as well when the docking clamps failed to release, which is why we're using Wonderbird Two's rescue line. What you'll need to do is attach it to the escape pod, then dock with the vacant airlock on that module of the lab. Get inside and give me a manual uplink to the onboard computer, I should be able to force the clamps open. Then 'Two just has to reel it in, and we should be a-okay."

"Easy peasy," Fluttershy said. "I hope."

"We've been listening in on your transmissions," Twilight added. "'Five and I agree, there's something suspicious about this situation, and you should absolutely proceed with caution. We have no concrete information as of yet, 'Five is currently trying to access the operational permit for Deepsea Echo, in case she can uncover anything more specific. Since it's a military operation we can't go pressing too much harder. If you want to hold back until we know more, we'll all support your decision.

Fluttershy considered this for a few seconds. "We don't know how long, or even if we'll be given any more information. When you're underwater, every moment counts, and I don't think we should waste any. I'm going to carry on."

Applejack watched the commotion from Wonderbird Two's cockpit, glancing down at the controls every few seconds to make sure the rescue line was unspooling correctly, and that the ship was maintaining its hovering position.

Even from this distance it was fairly easy to discern who was who in the crowd of ponies: the white jumpsuits were the detained ponies who had escaped the laboratory, while the crew of the flight deck could be discerned by their beige uniforms. The sole exception to the two groups was a lone figure clad in blue, in the centre of the group.

It looked like Rainbow Dash was stood in-between an ongoing argument. After the two of them had realised that the laboratory escapees were being arrested, she had disappeared back onto the bridge of the ship and emerged back on the flight deck shortly after. Applejack had watched her run over to the assembled group of ponies, positioning herself between the officers on the flight deck and their assembled prisoners.

Because Rainbow Dash wasn't transmitting on her radio, Applejack was forced to watch on from a distance, unsure of what exactly was transpiring below her.

Two more figures emerged from the same doorway that Rainbow Dash had exited onto the flight deck, and had charged over to join in the fray, another two beige-clad figures in a crowd facing a lone blue. To Rainbow Dash's credit, it didn't seem to dissuade her resolve, and she stood her ground. Whatever she was saying to the assembled ponies, she seemed to feel the need to stamp her front hooves a few times to make her point.

The smaller of the two ponies who had followed Rainbow Dash from the bridge answered with a stamp of both front hooves, before gesturing wildly towards the stern of the ship, where Wonderbird One sat.

Rainbow Dash stood motionless for a few seconds, then turned on the spot and stiffly started marching down the line of detained white-clad ponies, bound for her rocket.

"Hey 'Two," came her raspy voice in Applejack's earpiece. "I got bad news fo- WHOAH!"

In alarm, Applejack rose to her hooves. As Rainbow Dash had passed the last figure in the line of the laboratory ponies, the pony had sprung to his hooves and tackled her to the ground. It happened so quickly that Dash hadn't any chance of reacting or defending herself. Two of the beige uniformed ponies stood nearby were quick to respond, dragging the crazed figure off of Rainbow Dash. The blue figure rose on unsteady legs, and continued her retreat back to Wonderbird One. She walked at a quicker pace, taking a glance back over her shoulders as the white dressed pony flailed wildly against his captors' restraint.

"Whut in the hay? You 'kay there, 'One?"

"Y-yeah, I'm o-okay," Dash replied, not even trying to hide the quiver in her voice.

She didn't elaborate. Instead, she made short work of the distance left between her and her ship. Applejack watched as she scurried up the flight ladder, and after a few tense seconds, the ladder retracted and the downward-facing jets on Wonderbird One's fuselage roared into life. The rocket lifted into the air, away from the Seaquestria and settled into a hovering position a few hundred feet away from it.

"Ho-kay, sorry about that," came Rainbow Dash's voice again into Applejack's earpiece, the quiver no longer as noticeable. "As I was saying: bad news for diplomacy, they kicked me off the ship."

"Whut happened?"

"Well, I saw those ponies being treated like prisoners, when they could be sick or hurt after getting out of that lab. I went down there to try and... err... politely explain that they might need medical attention, and putting them in cuffs and leaving them out in the tropical sun might not be good for them."

"Politely?"

"Yeah."

"In them exact words?"

"...okay maybe not those words exactly, but that was the gist of what I was trying to say."

"An' 'ah take it the commandin' officers didn't take kindly to that?"

"Eehhhh, they called it 'insubordination' and told me to get my ship off their flight deck before they pushed it off and threw me in the brig."

"Outstandin', 'One. Well done, that's another military service that we ain't gonna stay on friendly terms with."

"Look, I'm sorry okay. But those ponies from the lab looked rough. Like, really shaken up."

"Is'n that why that feller jumped at you?"

For a few moments, Rainbow Dash didn't reply. The dull roar of Wonderbird Two's engines, normally a quiet sound in the background, seemed amplified as the time Applejack awaited an answer dragged on and on.

Finally, Rainbow Dash said "He was saying that he saw something down there."

"Somethin'? Whut kinda somethin'?"

"I don't know. He said it came out of the darkness and attacked them. And just as they pulled him off me he was screaming. He said..."

Applejack waited a few seconds, then asked "Said whut?"

"...he said it was their fault."

II: What Lurks Below

Fluttershy's eyes widened as the ivory-white hull of the Deepsea Echo loomed into view through her window. The schematic had done little to prepare her for the enormity of the machine, with each spherical module emerging the size of a building out of the darkness into Wonderbird Four's spotlights. She pulled back on her control yoke, the craft rising to a level bearing and approaching the nose of the front-most module. Through a series of large portholes, she could see the main control room of the vessel. Flashing red lights within illuminated control panels and a sophisticated array of levers, left abandoned as the occupants had fled the craft.

According to their information, the malfunctioning escape pod had been attached to module number thirteen. Not wanting to consider superstition, Fluttershy eased her thrust lever forward, pulling back on the yoke to pass above the stationary craft. She didn't even need to count off how many modules she was passing over: the designers of the lab had stencilled large numbers on top of each one. All she had to do was proceed to the thirteenth one.

"'Four, you read me?" came Rainbow Dash's voice into Fluttershy's earpiece, startling her.

"Loud and clear,'One. What's the matter?"

She listened as Rainbow Dash recounted the events that had transpired on the surface. How the laboratory ponies were all being arrested. How Dash had gotten herself kicked off the Seaquestria for standing up for them. How one of them had tackled Dash to the ground, and the panicked confession he'd made to her.

"He said something came out of the darkness and attacked the lab?"

"Yeah. You know fish and stuff better than any of us, does anything live that deep that could do that kind of damage?"

"Nothing I can think of," Fluttershy mused. "At least, nothing that I know of. There's theories about giant undersea creatures that could have inspired what we see in the mythology of some ancient pony societies, but nothing that's ever been proven."

"So something could be down there?"

"It could be," she admitted. "But the likelihood of that is so low it's not even worth thinking abo..."

Her voice trailed off. As the floodlights of Wonderbird Four had reached the twelfth module of the craft, a horrific sight had come into view. Fluttershy eased back on her thrusters to bring the craft to a stop. At the point where one of the spindly legs should have attached to the lab was only a stubby protrusion of twisted beams, hanging limp in a cloud of hydraulic fluid. A few feet back from it, a long trail of dented and scraped metal reached sternwards towards the thirteenth module. It was reminiscent of damage Fluttershy had seen on ships that had struck rocks or clusters of ice.

Except the angle was all wrong. The damage had only started hundreds of meters from the front of the craft. Conventional wisdom suggested that the front would have impacted first. And with its design, and the manoeuvrability it was capable of, any obstacle would have been easy to avoid.

She twisted one of her joysticks, facing Wonderbird Four out into the gloom and using her floodlights to light up the surrounding area. Where she might have expected to see a large rocky formation, or a towering hydrothermal vent, was only darkness. With another flick of her controls she aimed the submarine downwards, only illuminating the sea bed below her.

"Base from 'Four, can you see this damage?" she said into her headset.

"We can, 'Four," Twilight replied. "We're discussing it here, trying to work out what might have happened. My first thought was some kind of obstacle too, but evidently you thought the same. We can see as clearly as you can that there's nothing nearby that it could have hit."

Fluttershy tensed up, a question forming she already suspected she knew the answer to. "Is it possible that it hit something and kept moving before it stopped?"

"Negative. The automatic shutdown procedure would have kicked in the moment that an impact occurred."

"I really kinda hoped you wouldn't say that."

"Look, whatever's happened, right now our priority is to free the ponies trapped in the escape pod. Let's keep our head in the game, 'Four, and do our job."

"Copy that," Fluttershy replied with a squeak.

She pulled back on her controls, levelling Wonderbird Four off before she eased the thrusters forward again. The floodlights passed back across the hull of the lab as she progressed forward, more and more of the damaged plating appearing from the gloom. It was testament to the design of the structure that anypony had escaped. In oceans as deep as she was in now, any compromise in the integrity of the hull was likely to cause the entire section to collapse in on itself. This was due to the enormous pressure of the water at this depth. The metal was buckled, but it had not torn, nor had it caused a catastrophic failure.

The scrape continued from one module into the next, seeming to go on forever, until it finally yielded and faded away, ending just before a protrusion of orange metal jutting out from the side of the vessel. Fluttershy gave a start as she realised that in her fixation on the unexplainable damage, she'd missed the fact that she was drawing alongside the escape capsule.

She adjusted her controls once again, examining the small craft hanging from the side of the lab that now looked comically large in comparison. It was a bright orange cylinder, about twenty feet in length with no visible windows, pointed outwards from the side of the craft. With the combination of its colour and its proportions, it looked to resemble a giant can of soda embedded into the side of the of the spherical module. Aligning Wonderbird Four with the outer end of the escape pod, Fluttershy tapped a small button on her control joystick. This instructed the automatic bosun to hold its current position.

Various manoeuvring thrusters on the outside of the hull would counter any sudden currents that might cause Wonderbird Four to move unexpectedly. Fluttershy was then able to reach out to operate a second joystick, this one giving her control of a grappling claw on the end of a long metal arm. The claw still held the end of a cable, attached to Wonderbird Two almost seven miles above. Hanging from the end of the cable was a large magnetic clamp.

She eased the joystick forward, until with a satisfying thud the magnet jumped forward. It attached itself to the flat section at the front of the escape pod. Wonderbird Four lurched with this movement, and Fluttershy pulled a trigger on the backside of the joystick which instructed the claw to open and release its hold on the cable.

“’Two from ‘Four, we have a successful magnetic seal,” she announced as she tapped a button which instructed the arm and claw to retract back into its housing in the hull. “Keep the cable slack until I can get the docking clamps released.”

“Copy that, ‘Four, an’ well done,” Applejack replied.

Fluttershy pulled back on the control joystick, which disengaged the automatic bosun and tilted the nose of the submarine upwards. Taking care to avoid the hanging cable, she nudged the thruster forward and moved Wonderbird Four up and over the top of the module. Once on the other side, she switched the largest of her control screens onto the feed from the camera located at the rear of the craft, and began to ease her controls backwards.

Several months earlier, Rainbow Dash had pranked Fluttershy by adding a reversing siren when Wonderbird Four was configured to dock with an airlock using the universal seal at its stern. The onboard controls hadn’t been built to make harsh noises, so the resulting siren turned out as a gentle, rhythmic humming once every two seconds. To Dash’s surprise, Fluttershy had not only found it funny but it seemed to aid her concentration. The humming resonated through the cockpit as she eased her joystick, inching her craft closer and closer until, with a thud and a hiss, Wonderbird Four attached itself to the airlock on the lab.

"Base from 'Four, I've successfully docked with the lab. I'm entering now," Fluttershy reported, flicking a few switches on the overhead panel as she rose out of her seat.

"Copy that, 'Four, keep us updated."

After passing through two sets of waterproof bulkheads, Fluttershy found herself at the main airlock hatch at the rearmost section of Wonderbird Four. She checked her wrist-mounted display, confirming her suit was maintaining correct oxygen levels and air pressure. Then she reached up and pulled a large lever mounted to the hull. With a loud hiss the rear section of hull opened outwards into the laboratory, split across the middle like the tailgate of an SUV.

The inside of the vessel was dimly lit. Orange strips illuminated left and right, outlining the corridor in each direction at the points where the walls met the floor. Flashing red beacons hung from the ceiling, sending strips of light spinning across the dark walls. The interior reminded her of some of the more violent video games Rainbow Dash would enjoy playing. These games tended to involve underground facilities dealing with outbreaks of otherworldly creatures, ones that required a gentle but firm introduction to a machine gun.

Having already studied the schematics of the module she was currently in, Fluttershy already knew where to go. She switched on the small torch mounted on her helmet, and turned to her right to make her way towards the nearest watertight door. Each module was laid out the same: a narrow circular corridor looped the full width of each sphere, leaving a large room in the centre. The outer corridor was segmented into watertight sections, so if flooding ever occurred the breached section could be isolated and locked off to prevent a catastrophic failure that could destroy an entire module.

The purpose of the central room varied from module to module, with some containing accommodation, but most served functions associated with the maintaining and operation of the lab. In the case of the module Fluttershy was currently in, the internal room was designated as both a storage room and as a server farm for the various onboard systems. Given the current crisis, it worked to her advantage that the central room of the module contained a server farm. Direct access to the onboard systems would make it easier for Twilight to hack her way in.

Fluttershy progressed through several watertight doors, each of which gave a sharp hiss as it opened and a dull thud as it closed behind her. After passing through several segments, she reached a door that accessed the inner room. She pressed a button on the wall next to it, finding herself yelping with surprise and sidestepping as it opened and a small pile of fresh apples spilled out into the corridor. True to the schematics it was a storage room, and as she leaned through the doorway to let her helmet light illuminate the space within, she saw dozens of rows of shelves. Almost all the boxes and crates that each shelf had held were strewn across the floor, scattered no doubt by the impact that had rocked the lab.

With a grimace, Fluttershy stepped inside. She made an effort not to focus on the unpleasant squelching of the assortment of fruit and vegetables underhoof, instead focusing her attention on the far end of the room, where she could see the flickering lights of computer panels. It took some effort, including climbing over some wooden crates that had remained intact, but she soon found herself at the back of the room. The server farm was walled off from the main storage area, no doubt a design choice intended to keep the precious computer components safe from any potential contaminants. Large windows gave Fluttershy a view into the small dark space, where she could see several server towers sat flush with the circular outer wall.

She pushed through the door and closed it behind her, as her wrist display beeped to indicate a noticeable rise in temperature. This was likely a side effect from the emergency shutdown sending the computer systems into overdrive to keep the life support running and ventilation flowing. She tapped at the small display on her wrist, which slid up to reveal a compartment out of which Fluttershy retrieved a USB stick. Making her way over to an interface terminal, Fluttershy tapped at the keyboard to bring it out of sleep mode, and plugged in the stick.

"Base from 'Four, I'm in the server farm now. You should have access to it from my hard-line now."

"Copy that, 'Four, running diagnostics now. Stand by and give me a few minutes," Twilight replied.

Her computing skills must have been as sharp as ever, as ten seconds passed before the lights flickered back to life. Both the server room and the storage room beyond came into clear view. Fluttershy winced as the bright light filled her vision, the photoreceptive sensors on her helmet taking a few seconds to process the sudden change. They caught up, dimming and adjusting to reduce the glare. Fluttershy's eyes adjusted, and she took in a better view of her surroundings. As she looked through the window back into the storage room, something caught her eye.

"Base from 'Four, what's the signal range between the uplink and my computer?"

"Err... about fifty metres, maybe a bit less if it's between walls. Why?"

"I just want to have a look around these rooms. It's going to take you a few minutes, right?"

"Yeah it will. Have a look if you want, but stay nearby. It's a no-go on forcing the clamps to disengage from my end, I'll need you to do some manual inputs on the terminal once I've reset the system. 'Five is on standby if you need anything."

"Copy that," Fluttershy replied.

Leaving the humming computer servers behind, she stepped back into the storage room. On the far side of the room, hidden by the many rows of shelves, she could see a workbench against the wall. As she got closer she could see an assortment of scientific equipment. Racks of test tubes along the wall, an autoclave and a centrifuge teetering on the edge of the work surface, and a bunsen burner that was still spewing blue flames. A tap dripped into a sink sat next to the workstation, the gentle pittering of water hitting metal growing louder as Fluttershy drew nearer.

She passed the last shelf and froze. On the floor lay a smashed pile of glass and metal framework in a rainbow streaked puddle of chemicals. Whatever the scientists running the lab had been doing in this room, it was more than storage. The equipment here had been in use when the vessel was struck. There were half a dozen designated scientific laboratories on board, with all the same chemical apparatus she could see in front of her now, and must have been much better stocked.

The setup she had in front of her here was slapdash. What she had assumed from a distance to be a proper worktable, she could see on closer inspection was actually the top section of one of the rows of shelves. The test tubes hanging from the wall were held up by zip ties that had been glued onto the metal plates. There were several more machines she didn't recognise that, along with the autoclave and the centrifuge, were being powered by wires haphazardly pulled from gaps in the wall plating. This wasn't a proper lab. This was a poor imitation of one, thrown together by somepony trying to hide their work. Whatever she'd stumbled into, it wasn't good.

"'Five from 'Four, do you read me," Fluttershy asked.

"Loud and clear, 'Four," Rarity's dulcet tones chimed back. "I'm watching your video feed darling, I must say I don't think that's a properly built laboratory in the slightest."

"It's not. Not at all. Whatever they've been doing here, they don't want it seen. My guess is they've put this here so they can quickly hide it all if they ever get boarded."

"But why in Equestria would they do that?"

"I have a hunch," Fluttershy mused, her eyes falling on the centrifuge. "They're working on something they don't want anypony to see."

She walked over to it and lifted the lid, revealing eight sealed vials. Each one contained a liquid of dark, sea-green colour. Fluttershy gingerly picked one up, holding it up to the light to examine it.

"Very peculiar indeed," Rarity marvelled. "Shall I run a chemical analysis on it?"

"Sure, I guess we should know what we're looking at here," Fluttershy said, popping the lid off of the vial and placing it down on the worktable.

She tapped at her wrist display again, opening the compartment to retrieve a small pipette. She dipped it into the vial, soaking up a few small drops before returning it to its slot. She slid the display back into place, and it trilled a few musical beeps at her to confirm it was analysing the new substance. Not wanting to take any further risks, Fluttershy put the lid back on the vial, and returned it to the centrifuge.

"Running chemical analysis now, 'Four," Rarity confirmed. "I can tell you straight away, I don't think it's anything 'recreational', it doesn't appear to have any toxins in it."

"Hooray," Fluttershy replied, jokingly punching the air with a hoof. "That's one thing they're not up to down here. It still doesn't explain all the secrecy."

"Yes, it's a little 'cloak and dagger' for a gardening club."

Fluttershy's ears perked up. "Gardening club?"

"Hmm? Oh no, don't mind me darling, just a little joke. There's a large shrub on one of the shelves behind you, I saw it when you walked past it."

She turned and looked around, spotting where Rarity had meant. It was on a low shelf, hidden out of view of the server room windows, so she wouldn't have spotted it if she hadn't come out to have a look around. It certainly looked out of place, as much so as the thrown-together lab did among the rows of shelves. But there was something she couldn't put her hoof on.

Fluttershy walked over to it, leaning in for a closer look. It was large, about the size of an exercise ball, and it wasn't planted in a pot. It had been cut at the roots and laid out sideways on the shelf. Its stem was green and thick, much thicker than she'd seen on any other shrub. Even up close, there was something off that she couldn't quite wrap her head around. It didn't actually have leaves, it had large flower heads, almost like...

She froze. Her mind reeled. It couldn't be...

Fluttershy double checked her wrist display. Confirming the air was safe to breathe, and was of sufficient pressure, she reached up to her helmet, and twisted it off. It gave a light hiss as the safety seals disconnected, and Fluttershy placed it on the floor next to her. Then she leaned in closer, her face inches from the plant, and inhaled deeply through her nose.

She was right. It was.

"'Four to 'Five, come in," she called as she re-donned her helmet, clicking it back into place. "It's not a shrub. It's broccoli."

"Don't be ridiculous, darling," Rarity scoffed. "Broccoli doesn't grow that anywhere near that large."

"Maybe it does if there's an illicit laboratory nearby producing a chemical that nopony is supposed to know about?"

The line was silent for a moment, before Twilight Sparkle's voice cut in. "It's theramine."

"Theramine?" Rarity asked. "You mean that strange musical instrument."

"That's a theremin. Theramine is an outlawed food additive that was trialled a few years ago as a potential solution to global hunger. It was used to accelerate crop growth as well as increase yield, but then livestock started to eat it. It caused uncontrolled growth in any animal that consumed it, and the enlarged creatures displayed dangerous levels of aggression. The UNEQ had to step in to ban the substance after an incident involving... well, alligators."

Silence hung in the air again for a few seconds, Fluttershy pondering the consequences of a giant, hyper-aggressive alligator, and she expected Rarity was as well. It was a chilling prospect.

"So why is it here?" Fluttershy asked.

"Best guess? They're trying to work the kinks out of it in secrecy. Maybe they had a breakthrough recently? That might explain why they missed their last surface rendezvous. Stay down here, keep working until its done."

Fluttershy considered this. If the scientists on the laboratory were working with illegal substances, it seemed a plausible explanation for why they hadn't met with their surface rendezvous as scheduled. But a more troubling thought crossed her mind as she looked around, again spotting the sink beside the workstation.

"And what if they dumped any of the chemicals overboard?" she asked.

"Impossible," Twilight declared. "Pintocific regulations prohibit that. Each module on Deepsea Echo has its own standalone storage tank for waste water. It's subject to the same laws that prohibit cruise ships from dumping their sewage overboard."

"Okay, it was just a thought," Fluttershy said, though she thought she heard doubt in Twilight's voice. "How are you getting along with the computers?"

"I'm almost finished, actually."

"Do you need me to do anything?"

"Just be ready to go in the server room, please. I need to force a full system reset, after which you should be able to release the pod from your end. I'll make sure 'Two is standing by for the release."

After casting one more uncertain glance at the makeshift laboratory table, Fluttershy made her way back to the server room. As she stepped in she noticed it felt much cooler than before, the computers no longer operating at battle stations to maintain the various onboard systems. She positioned herself at the terminal where she had plugged her hardline USB in, then called in to Twilight that she was ready to go.

All the ceiling lights went out in unison. The screen of the terminal switched off. Darkness and silence fell across the room, as the multitude of fans keeping the servers cool slowed to a stop. The illuminated panels on the outside of each server unit went dark, one by one until Fluttershy found herself in total darkness and utter silence.

Then the screen on the terminal flickered back on, only showing a spinning progress wheel on a black background. It beeped at Fluttershy once. Then twice. For a few tense seconds, nothing else happened. Then the fans in the server room began to whir back into life. The panels on the server units flickered back on one by one, and the ceiling lights followed suit moments after. Finally the computer terminal gave a chime, and the loading screen vanished to make way for a simple interface of various menus and sub-menus.

"System reset complete," Fluttershy reported.

"Copy that, 'Four," Twilight replied. "You can disconnect the hardline now, this part I'll need you to do manually."

Fluttershy stowed the USB device back in its compartment on her wrist computer, then listened carefully to Twilight's instructions. She followed along each step as dictated, navigating her way through the maze of administrative controls. Apparently the designers of the laboratory had never thought it was possible for the clamps holding the escape pods to fail. Twilight resetting the computers had been necessary to create a backdoor into the maintenance software, which was only normally accessible when the craft was in a dry dock at the surface level.

As instructed, Fluttershy eventually found herself at the menu that controlled the various functions of the escape pods. Even though Wonderbird Four had docked with the vacant docking station on the port side of the craft, the computer registered it as a vacant dock. The starboard dock however, despite still being connected, only showed an error message. Again, a design oversight. The computer simply did not understand how the water seal had breached, but the pod was still docked. The designers didn't seem to have the same knack for safety features as Twilight.

They did, however, get at least one thing correct. The latches holding the escape pods in place operated on a spring-loaded ram, held into place by a locking pin and hydraulics. Rather than using the hydraulic pressure to push open the latches, the system instead had a two step system. The locking pin would release the ram, then a valve would be used to drop the hydraulic pressure. This would allow the springs to push the ram and the latches would move aside, detaching the escape pod.

Navigating her way through a couple more sub-menus, Fluttershy found the controls for the release mechanism. The locking pins had released, but the hydraulic pressure was still at full. She marvelled at how Twilight had been able to figure out the problem and how to resolve it. All within the hour it had taken them to get from Harmony Island to the danger zone. She entered the command to release the hydraulic pressure and the computer requested confirmation. She pressed 'confirm' and watched, as the bar representing the release ram began to inch from one side of the screen to the other.

"Docking clamps released," she declared.

Fluttershy smiled to herself, satisfied at the job well done. Though she only had a few seconds to enjoy the satisfaction, after which a deafening sound of screeching and scraping metal erupted though the walls of the lab. She operated on raw instinct, dropping to her belly and covering her head with her hooves as the world around her creaked and moaned. The floor began to shake, sending waves of vibrations up into her chest. If the module collapsed under the water pressure, her foetal position would do her little good.

But she didn't dare move.

She imagined this was what it sounded like at the epicentre of an earthquake. Time seemed to slow to a crawl, but finally the noise stopped. The floor beneath her heaving chest gave one last jolt, and settled back into place. The silence was deafening after such a horrific noise. The Fluttershy of years gone by would have been immobilised in place by such a traumatising event. But this Fluttershy had spent over a decade building herself up to be more confident in herself. She knew, from a large part of that decade being spent training as an aquanaut, she didn't have the luxury of time.

"Base from 'Four," she declared as she rose to her hooves, making her way out of the server room and towards the door. "The laboratory was just hit by some kind of seismic activity. Is the escape pod clear yet?"

"Err, sorry 'bout that there, 'Four," came, to Fluttershy's surprise, Applejack's voice in reply. "There musta been some kinda current down there, swung the pod back at the lab as 'ah started reelin' her up. Scraped along the hull somethin' fierce but 'ah don't reckon it did any damage that was too severe. Not from whut 'ah can see, at least. The pod ain't leakin' or nuthin'."

"Is it clear from the lab, 'Two?" Fluttershy asked again, this time directing the question at Applejack.

"Affirmative, 'Four. 'Ah'm reelin' her in at full speed, she's clear of the lab. With the cable comin' up as fast as it'll go, should only be 'bout half 'n hour an' then we'll have her out in the dry."

"Copy that. Base, do you still need me on board the lab, or am I cleared to return to Wonderbird Four?" Fluttershy asked as she made her way back across the room.

"Get out of there and escort the pod back to the surface please, 'Four. Did the lab sustain any damage from the impact with the escape pod?"

Fluttershy paused at the display panel near the door. It displayed a floorplan of the module she was in. She recognised the layout from the schematics she'd looked over during her descent in Wonderbird Four. The central room was highlighted green, as were most of the segments that represented the assortment of watertight bulkheads that divided the outer corridor. On one side of the module, however, were two segments that were flashing orange.

"The computer is detecting water breaches in two compartments," Fluttershy reported back. "The doors will be locked to prevent further flooding, but it's the opposite side of the module to Wonderbird Four. I'll be able to get back without any problems."

"Copy that, 'Four, and glad to hear it."

Passing back through the door, Fluttershy began to retrace her path from her earlier arrival back to Wonderbird Four. When Twilight had reset the computers, it should have returned the corridor lighting to its normal mode. However this must have been undone by the breaching of the two watertight compartments, as it was still dimly lit. Even the emergency beacons were still spinning.

"'Five to 'Four, do you read me?" Rarity's voice chimed in once again on Fluttershy's radio.

"Go ahead, 'Five."

"I was listening earlier, regarding what you said about dumping chemicals overboard. Yes, we clarified with base that they don't do that, I know she said there were laws against it, but I did some digging on the design of the laboratory, just to clarify some things."

"Clarify what, exactly?" Fluttershy asked.

Rarity cleared her throat. "Okay, so essentially: we know the laboratory is required to surface weekly. This is as much a maintenance requirement as it is a regulatory one. Since the designers built it to Pintocific standards, it was built under the assumption that a weekly rendezvous would be made. For resupplying and such. But also, as it turns out, part of that weekly rendezvous includes a full purge of the waste water tanks onto the resupply ship. It brings them the essentials while taking their waste away for processing."

Fluttershy stepped though the last watertight door and onto the ramp of Wonderbird Four's rear airlock, processing this information. "So how long could those waste water tanks last between each rendezvous?" she asked, closing the ramp behind her.

"Exactly what I wondered," Rarity said, evidently pleased Fluttershy had clocked on to the correct piece of information. "The lab was designed to account for redundancies, and they always carry three times as many supplies as they need at any one time. Three times as much food, for example. The waste water tanks are the same. Emptied weekly, and they have the capacity for three weeks. Given an assumed average water consumption, of course."

"And the lab has been underwater for a month."

"Therein lies another redundancy. In case of emergencies and to prevent the crews exposure to hazardous water, each tank will automatically purge itself and dump its contents when the level reaches critical. The crew might have gotten by with their food supply if they rationed carefully, but there was no chance of them overriding this function."

Her mind reeling, Fluttershy began to join the dots as she sat back down in Wonderbird Four's cockpit. A manic scientist declaring something had attacked the lab. An enormous scrape along one side of the laboratory. The lack of any clear source of said enormous scrape. A secret lab working on an illegal substance know to cause uncontrollable growth in animals.

"So the question remains," Rarity added. "Is not if they've accidentally spilled a growth substance into the water."

"It's how much have they spilled." Fluttershy concluded.

Her lightbulb moment was interrupted by a loud ping from the console in front of her. She'd been so lost in thought that it took her a few seconds to compose herself and locate the source of the noise. She looked up at the sonar screen, where a shape had just faded away. A few seconds later, the sonar pinged again, the shape reflected back at Wonderbird Four now much clearer.

It was big. Very big, and approaching with alarming speed. By the scaling on her sonar, Fluttershy estimated it to be about eighty feet in length. It was less than a mile away but with every ping it drew nearer and nearer. Fluttershy's heart began to race as she disconnected Wonderbird Four from the lab. The airlock hissed as she let her sub drift away in the current, watching as the anonymous shape got closer.

Her rational mind was in conflict. In all likelihood it was another submarine approaching. The distress call had been made on an open frequency, after all. Maybe it had reached somepony else, and not just Wonderbird Five? But on the other hoof, the escape pod being dragged and scraped across the hull of the lab had made a lot of noise and vibration. To any predatory creature lurking nearby, it would have been akin to ringing a dinner bell.

The shape on the sonar slowed its charge, bringing itself to a halt about a quarter of a mile away. Fluttershy's breath caught in her throat as she nudged on her joystick. Wonderbird Four spun, her nose and her floodlights now pointed in the direction of the shape but still revealing nothing. It had to be some kind of submarine, it just had to be.

Then out of the gloom, it began to appear. Slowly inching into view. A gray conical shape, pointed straight forward, grew and grew as it thrust itself forward into the light. Then came the teeth. On the underside of what Fluttershy now realised to be a snout, sat a row of wicked-looking teeth. Horrible white needles, sticking out in every which direction. So fixated was Fluttershy on processing this, she gasped when she looked up and saw that the creatures eyes had drawn into view. Terrible orbs of pure black, that somehow seemed to absorb all the light around them.

For a horrifying few seconds, Fluttershy's mind failed to come to terms with anything other than the raw image in front of her. She looked from eye, to tooth, to snout. A single descriptor formed in her mind: Goblin Shark.

The gargantuan creature hung there for a few more moments. Only its head was illuminated by the powerful floodlights of Wonderbird Four. It dawned on Fluttershy how much her submarine was completely dwarfed by the shark in front of her. It felt like a sick, twisted spin on an old expression: the shark may have been in her headlights, but in this scenario, she was most definitely the deer.

Its jaw twitched and it began to surge forward again, barrelling straight towards Fluttershy.

III: Facilis Descensus Averno

Rows of teeth. A gaping abyss beyond. A piercing shriek that escaped Fluttershy’s mouth without any conscious intention. All things that passed through her head in a split second, as the monstrous shark bore down on her. Its jaw began to jut forward, extending out of its mouth in a gruesome twist of evolutionary development. Like it was reaching out of it to clutch the small yellow craft between teeth the size of tree stumps.

But Fluttershy's reactions were quick. She slammed down on the thruster lever. Wonderbird Four jumped forward like a bullet fired from a gun, racing to meet its foe head on. At the last possible second she twisted her yoke to the left, sending the submarine into a barrel roll. The mighty jaws slammed shut out of view from the right hand side of the windscreen, and a terrifying jolt erupted through the ship. The yoke grew heavier in her hoof as Fluttershy felt Wonderbird Four try to pull itself out of the roll, but she held it firm. Warning lights flashed across the control console, but Fluttershy’s attention was elsewhere. Huge grey fins shot past the windscreen, then a tail as tall as a building, and then only pitch blackness as the creature passed by.

Pulling herself out of the roll, Fluttershy looked to the rear cameras. The shark was turning to pursue, the enormous tail whipping around as it twisted. She groaned as she watched the tail impact the side of Deepsea Echo. The lab module she had been in moments before seemed to leap upwards as it imploded. It had been pushed beyond breaking point from sustaining so much damage. Neatly it detached itself from its neighbouring modules, and the perfect sphere shrank down to a shrivelled husk in a fraction of a second. All the air was pulled out of it in a violent burst of bubbles. No longer able to maintain buoyancy, it dropped like a stone to the ocean floor.

With another twist of her yoke, Fluttershy dove down and right to skim the sand below her. But the movement surprised her. It was sharper than usual, more sudden, less controlled. She dared a glance at the controls, where the warning lights indicated structural damage. Another glance to the cameras that faced outwards from amidships. Where she might have expected to see the starboard control fin stretching out into the gloom, there was instead only half of the fin. It ended at a grim break of twisted metal and dangling wires.

She allowed herself a few precious seconds to process the image. Wonderbird Four’s onboard computers were very similar to the fly-by-wire systems on her airborne sisters. They would partly be able to compensate for the difference in handling the loss of the control fin would cause. At least, it would stop it from being uncontrollable. But Fluttershy could feel the difference in how it felt. It was a subtle pull to the right, which would make left turns more sluggish and right turns feel sharper. She’d trained for this. She could handle it.

Looking back to the main rear camera, she could see the shark still giving chase. Its jaws gnashed and flailed, shooting forward out of its mouth with each attempt to bite down. But as she’d hoped, her little submarine was generating a turbulent current of wake as it raced mere feet from the sand on the ocean floor. The sand rushed upwards as the submarine passed over, creating a cloud that grew ever murkier as Wonderbird Four accelerated faster and faster.

Relief flooded through Fluttershy as the shark gradually became a smaller and smaller image on her screen. She was faster than it, even with a damaged fin. It was only when it disappeared completely from her screens that she realised she’d been hyperventilating. She took a few long, deep breaths as she eased back on her thrusters. Then, she checked the radar screen. It had given up the chase, and was turning back away from her.

“B-b-b… base from ‘Four. Do you read me?” she said, feeling a tear drip down her cheek.

“We hear you ‘Four. Are you okay?” Twilight’s voice replied, taking on the gentle and mothering tone she usually reserved strictly for princess duties.

“Y-yeah. I’m okay. Just a little, um… spooked.”

“I think under the circumstances, spooked is an entirely understandable reaction. Now, as ‘One said earlier, you’re more familiar with marine biology than any of us. Can you tell us what that was?”

Fluttershy took one more deep, calming breath, and then explained. “It’s a goblin shark. Some researchers call it a living fossil, the last known living species of a genus that goes back hundreds of millennia, maybe even older. They’re very rare and only live in deep water, but they’ve never been found this deep before. I didn’t even know they could survive this deep.”

“And I’m guessing they aren’t supposed to be that big?”

“No. If theramine causes abnormal growth, then we’ve just seen proof of it. But I guess there is some good news, juveniles tend to be found in shallower water. So if it’s down here in the deepest part of the ocean, it’s a fully grown adult. That means it won’t get any bigger… at least I hope it won’t.”

“Where is it now?”

“It gave up chasing me once I started to outrun it,” Fluttershy explained, expanding the view on her radar screen to show her a wider area. “There’s no point in wasting energy hunting down something that can go faster than you.”

But something nagged at the back of Fluttershy’s mind as she watched the shark’s shape move across the radar. It had turned tail completely after abandoning its hunt, and turned around to retrace the path they’d taken away from Deepsea Echo. It was heading back towards the lab. Back to the source of the noise and vibration that had drawn it close in the first place. The noise made when Wonderbird Two had accidentally dragged the escape pod across the hull of the lab.

As realisation dawned on Fluttershy, she near-enough felt her heart drop into her stomach.

“It’s going for the pod!” she shouted into her microphone as she fired up her submarine’s thrusters again, turning one-eighty to pursue the shark.

“What? How do you know?”

“Sharks hone in on noise and vibration. It couldn’t catch Wonderbird Four, so it’s going for the next loudest thing. That cable is attached to Wonderbird Two. The vibrations from the vertical thrusters… it must be deafening!”

“Copy that, ‘Four,” Applejack’s voice interjected, sounding panicked. “Performin’ emergency ascent.”

Seven miles above, Fluttershy knew Wonderbird Two would be rising upwards into the sky as Applejack pushed the vertical thrusters to full power. She’d been on board the craft during training manoeuvres, and it wasn’t a comfortable experience. Onboard Wonderbird Two, Applejack would be pushed down hard into her seat, and the ponies in the escape pod were in for a wild ride too. But it was very effective. Despite its immense size, Wonderbird Two could accelerate upwards at incredible speeds.

“What are you going to do, ‘Four?” Twilight asked.

”Give it a better target,” Fluttershy said, her voice quivering slightly.

Once again, Wonderbird Four accelerated forward. Fluttershy pulled back on the yoke, climbing upwards as she followed the radar pings of the enormous shark. It was rising fast, bearing down on the tiny escape pod that dangled at the end of Wonderbird Two’s cable. While Applejack’s manoeuvre would indeed get the pod out of the water quicker, it had its own drawbacks. With its engines going full blast, the vibrations of the cable would have increased tenfold. This, and the pod would be thrashing around as it dragged through the water. It had just turned into prey that would have been ten times as inviting as before. There was no way of knowing whether the shark would give up the chase now as it did before.

Tense moments passed as Fluttershy drew nearer and nearer to the shape on radar. Following its trajectory, she kept pulling further back on her control yoke. Very soon she found herself pressed hard back into her seat. The nose of Wonderbird Four rose at a near-vertical trajectory. Swishing back and forth, the tail of the shark drew into view of her floodlights. The submarine began to sway left and right as it rose. She was starting to ride the turbulent water caused by the thrashing tail.

“Firing sonic charge,” she said, lifting her hoof from the thruster lever to flick a switch on her overhead panel.

A small missile rocketed out of the nose of Wonderbird Four. Fluttershy allowed it a couple of seconds to draw alongside the shark, before she hit the manual detonation switch.

The sonic charges onboard the Wonderbird machines were similar in appearance to an explosive charge. But rather than using incendiaries, they released huge amounts of energy in the form of a wave of air pressure. They had been Twilight’s invention, and had proved very useful in controlled demolitions as they didn’t release shrapnel or debris. The rocket that held the charge could even be re-used, if it could be recovered.

For the effect that the charge had on the shark, Fluttershy could have been forgiven for thinking she’d accidentally fired an explosive charge. It lurched to the side, writhing and thrashing as the powerful pressure wave sent its senses into overdrive. Fluttershy eased back on her thrusters. The shark seemed too pre-occupied by its own pain to continue giving chase to the escape pod. The leviathan continued its frenzied dance, with Wonderbird Four’s floodlights giving Fluttershy a clear view. She whimpered as she watched. Her basic morals and instincts were in conflict with the sight of a wounded creature in front of her.

Then, slowly, it stopped. It hung there in the murk, as far as Fluttershy could tell seeming more dazed and confused than anything. Occasionally it twitched and spasmed, its gills fluttering as it seemed to regain its senses. Fluttershy could hear her own pulse drumming loud and fast in her ears as she looked into its eyes. Like all shark eyes, there was no colour, and no white either. Just solid orbs of pitch black, betraying no thoughts and no emotions. Eyes that reflected the primal nature of their owners. Remnants of a time before civilisation, a time of carnage and monsters.

The shark became deathly still. Then, with a flick of its fins, it turned to face Wonderbird Four head-on.

As before, Fluttershy’s reactions were like lightning. She pushed forward on her yoke and sent the submarine into a dive, setting her thrusters to full power. The shark, either too slow or too dazed, missed by a wide margin as it tried to bite down on Wonderbird Four. Its teeth found only empty water, but it whipped around to give pursuit. Fluttershy saw a flash of grey in her peripheral vision. Time seemed to slow down as the tail fin whipped towards the submarine. But as milliseconds dragged by, Fluttershy found herself unable to react in time.

An almighty boom rocked Wonderbird Four. The entire craft lurched hard to the right, spinning out of control. Fluttershy felt the wind knocked out of her lungs as she was thrown around in her seat. Red lights danced across the control panel. Warning alerts pinged in a twisted symphony of chimes and tones. Through sheer willpower, Fluttershy kept her hooves firmly on the controls. She winced as she steered herself out of the spin, maintaining her vertical dive. She was still alive, but the shark had gotten its own back for the shot she’d fired.

“Uuurrrggghhh…” Fluttershy groaned as she struggled to find the air to form words. “‘Four to ‘Two… do you read me?” she asked between gasps.

“Loud ‘n clear,” Applejack replied. “Hang in there, sugarcube, ‘yer doing jus’ fine.”

“How long… until you get that… pod clear?” Fluttershy asked, her breath coming back to her.

“Five more minutes. Jus’ five more minutes, ya’ can do this.”

“Copy… that.”

Gritting her teeth as she looked to her rear camera, she saw the same horrific view as earlier. The gigantic head, jaws snapping over and over as the shark gave chase. Fluttershy’s hooves danced on the controls. She balanced the thrusters, maintaining the distance between Wonderbird Four and its gargantuan pursuer. She had to hold its attention long enough for Applejack to get the escape pod clear.

For a few moments, Fluttershy dared to look down at the warnings on her console. On top of the damage done to her starboard control fin, the port side had taken a serious hit from the impact with the tail fin. There were error messages flooding across the screens. The camera feed showing the port side was only displaying static. While she couldn’t see if the port fin was damaged or not, the feeling of the controls didn’t seem to suggest it. If she was lucky, the shark’s tail had only impacted the hull, and missed any control surfaces.

Suddenly a wall of beige filled her windscreen. Fluttershy yelped as she pulled backwards on the joystick, avoiding barrelling into the sea floor with inches to spare. She felt Wonderbird Four’s port fin brush against the sandy bottom. At least, she realised, that meant it was still intact. Her eyes darted up towards the rear camera feed, where she saw the shark follow her trajectory. As it had been travelling full-speed, it struggled to slow down. It managed to pull itself out of the dive, but the momentum carried it down and it impacted the sand in an almighty belly flop. Plumes of sand billowed out in every direction. Fluttershy eased off on her thrusters as it vanished in the cloud it had kicked up.

The respite was short lived though, and the pointed snout emerged from the cloud of sand. The creature's movements seemed slower, like it was winded. Fluttershy winced again, not through her own pain but out of sympathy. With so much of her life she’d dedicated herself to the care of animals, it seemed like an awful twist of fate that she should be here. Trading blows with a creature that knew no better. Her chest ached as she pushed forward on the thrusters again, and Wonderbird Four raced away. The shark shook itself away from the cloud of sand, gnashing its jaws as it sought out the yellow submarine that seemed hell-bent on taunting it.

“Base from ‘Four, come in base,” Fluttershy said.

”Go ahead ‘Four, you’re doing great. Keep it up for a few more minutes,” Twilight replied.

“I need to know something about this theramine stuff. You told me there was an incident involving alligators. Tell me what happened.”

There was a long pause before Twilight spoke. “It happened in South Amareica. There was a research station based in a river delta, the theramine was released into the water supply by mistake. It was meant to be circulated through the pipes that water the crops, but it ended up in the waste water. The local alligator population got a heavy dose, then they attacked and destroyed the station. Nopony was hurt, they all managed to evacuate in time.”

”And what happened to the alligators?”

“Look, Fluttershy…”

”Tell me.”

“...the alligators had to be euthanised. They were too big and too aggressive. They posed too great a risk to the local ecosystem, and if they’d roamed to any nearby towns… the UNEQ couldn’t take that risk, so they did what they had to.”

Thoughts reeled through Fluttershy’s head so fast, she found herself caught by surprise as the Deepsea Echo loomed in front of her again. This time she was approaching it from the side. From her positioning, she guessed it to be the portion of the lab to the rear of the module that had imploded earlier.

Wonderbird Four passed below it at speed, zipping between the spindly legs. The chance to wiggle the yoke as Fluttershy steered herself through a clear course re-affirmed the damage to the control surfaces. Alternating between a left and right turn, the yoke went from sluggish to sharp. Her hoof tightened around it.

Fluttershy watched the rear cameras in a mixture of fascination and horror as the shark charged at the lab. It careened through the joint between two modules like a knife cutting through sand. The two modules imploded in a violent shower of bubbles much like the one Fluttershy had seen earlier, triggering a chain reaction. All the remaining modules in that section imploded one by one, as they were dragged along in the sharks wake.

“Base,” she said as she felt butterflies dance in her stomach. “If this shark escapes the trench, how bad will it be?”

“It… um… er,” Twilight stuttered. “If it… if it gets out of the trench… ‘Four, if you’re thinking what I’m thinking, you don’t have to do this.”

“Please…” Fluttershy’s resolve finally broke, her sentence interrupted as she let out an audible sob. “Just tell me, yes or no. If it gets out of the trench, will anypony get hurt?”

“I think so, yes.”

Tears streamed down Fluttershy’s cheek as she formed a course of action in her head. It went against everything she stood for, but she’d made an oath when she joined Equestrial Rescue. The safeguarding of pony lives, at any cost. The shark, still chomping its jaws at Wonderbird Four, was a victim. An innocent creature, mutated and deformed by thoughtless ponies. If they hadn’t been performing illegal experiments, it wouldn’t have grown to its humongous size. It wouldn’t be in a frenzied, bloodthirsty state. Nothing about the situation was fair.

Fluttershy took a steadying breath. Resignation. That was the word, she thought. It was resignation to the task at hoof. She really didn’t want to do it, but she had to. She grimaced, her ears falling limply at either side of her head. Pulling back slightly on the thruster, she allowed the gap to the shark to reduce. Fluttershy watched it grow slightly larger on the camera feed as she nudged the yoke to the left. Wonderbird Four shifted its bearing very slightly, banking left as the shark followed.

Then, quick as a whippet, she threw the yoke hard to the right. Using the sharpened steering to her advantage, she caught the shark by surprise with the leftward feint. With a determined push of the throttle, she applied full power. Wonderbird Four darted to starboard, the shark still turning left. The rear camera showed Fluttershy exactly what she needed to see: the shark stopping, writhing around in confusion. Its senses caught up mere moments later, as it located its target and bore down on it. As she’d hoped, Fluttershy had managed to double back on herself while maintaining a safe distance between her and the shark’s teeth.

Delicately, Fluttershy began to ease off the throttle in short bursts. Not enough to stop her dead in the water. But just enough to slowly bring the distance down between her and the shark’s head. Her senses were going haywire: red lights still flashed on her console, warning alerts still sounded through the cockpit. Wonderbird Four’s turbines hummed away. But Fluttershy tuned it all out, solely focused on this one task.

She held her breath as, like she’d planned, the remaining modules of Deepsea Echo appeared from the gloom. Instead of passing under it, she had positioned herself to be on a collision course directly with the joint between modules. She lifted off the throttles once. Twice. And a third time, bringing the tailfin of Wonderbird Four within inches of the tip of the shark’s snout. The huge jaws had stopped snapping wildly. It seemed to realise that the prey was almost within biting distance.

Time slowed down. The massive spheres of the laboratory grew larger in her windscreen. Closer and closer she drew. Every instinct in her body screamed at her to abort, to pull up, to turn away. She kept her hooves on the controls, not daring to move an inch. She could distinguish different markings on the side of laboratory modules now. A flash of red lights through a porthole. The reflections of her own floodlights pointed back at her.

She pulled back on the throttle again. The jaw of the mighty shark, now entirely taking up her rear camera, twitched. Fluttershy pushed her yoke down and right, and felt the port fin of Wonderbird Four clip the outer hull of the lab as the wall of teeth opened up behind her. It leapt forwards with the intent of closing around the little submarine. True to Fluttershy’s plan though, the jaw instead found itself attempting to close around a large, metallic object. An object that impacted the jawline of the shark at a speed exceeding sixty miles per hour.

The entire world seemed to explode around Fluttershy as she pulled back on the yoke, too little too late as Wonderbird Four landed hard on the sea floor. It skidded along the sand on its belly for what felt like forever. The view outside her windshield was dominated by waves and waves of bubbles. She felt the accompanying booms of laboratory modules imploding one by one. The submarine lurched as it bumped across sand and rocks. Fluttershy would never need to visit Tartarus, if there was indeed a hell then it could only be exactly like this. When the submarine finally drew to a stop, the noises outside continued unabated. Her eyes were clenched tightly shut. She kept herself braced in her seat. For a minute. An hour. A day. Time was meaningless as a nightmare raged around her.

And then, as quick as it had started, it stopped. All was silent. Fluttershy opened her eyes in time to see the shrunken remains of the lab modules, no longer linked together, fall one by one to the seabed in front of her. Gulping, she tested her thrusters. Wonderbird Four stirred. She pulled back on the yoke and pushed the throttle forwards, lifting up off the sand. Fluttershy turned the submarine to the left. The illuminated area in front of her was darker than it had been before. She realised she had lost some of her floodlights as she’d crashed down onto the sand.

To Twilight’s credit, Wonderbird Four had taken a beating today, but hadn’t broken down.

As Fluttershy spun around further, the remaining floodlights lit up a dark shape resting on the sand. She didn’t need to get a closer look, she could see it from where she was. Fins lay motionless. Eyes, still dark and devoid of any emotion, but somehow more vacant and empty. The lower jaw, limp and lifeless. The surrounding water starting to develop a red hue. She’d succeeded at her task.

Grief and exhaustion finally overwhelmed the adrenaline that had been keeping Fluttershy alert. She leant back in her chair as tears flooded her cheeks. She sobbed, her cries loud and unrestrained. She felt as cold and as dark as the water that surrounded her and the poor creature she had condemned to this fate.

Twilight Sparkle watched the sun inch ever closer to the horizon. Applejack was sat next to Rainbow Dash, the other side of Twilight’s desk, the two of them recounting the events of the day as they had witnessed them. But the alicorn’s focus was drawn out the window. The sky was turning a beautiful shade of orange, one of Twilight’s favourite things about this tropical region of the world. The weather around Harmony Island was almost always warm and beautiful. And even when a storm did strike, it was brief.

Twilight considered this as her eyes flicked to the lone figure on the balcony. Much like the weather, Fluttershy almost always radiated warmth and beauty. But what had happened in the Mareiana Trench didn’t bear thinking about. A dark cloud hung over Fluttershy’s gentle spirit. They had to make sure she could see herself through to sunny skies again.

“An’ thas when we got the escape pod reeled outta’ the water,” Applejack concluded.

“Problem was,” Rainbow Dash interjected. “To get them out quickly, we had to pull them up too fast. The eggheads inside, all came out with the bends.”

Applejack cocked her head. “The whut now?”

“The bends. Y’know, decompression sickness. Happens to divers sometimes.”

Twilight shifted her attention back. “And were the Navy able to deal with them?”

“Well, they got ‘em all sorted out al’rite, medicinally speakin’,” Applejack said. “As for legally speakin’? Well that’s a mite more complicated.”

“Those dopes were dumb enough to bring bottles of that thera-stuff into the escape pod with them,” Rainbow Dash guffawed. “Caught them red hoofed, pants down, guilty as charged!"

“It’s not uncommon for scientists to value their work over their well-being,” Twilight said, nodding her head. “But the main thing, there’s nopony hurt or missing. Correct?”

“Affirmative,” Applejack said.

“Yessiree,” Rainbow Dash agreed.

“Excellent. Another successful mission. I’m going to reach out to my Naval contacts tomorrow, see if we can’t smooth relations over after Rainbow Dash’s little altercation with Captain Jetstream.”

Dash’s cheeks flushed as her ears folded back in indignation. “H-hey, that’s not exactly all my fault! If that prissy featherhead had just told us what we were dealing with, we could have come up with a different plan. She almost got Fluttershy killed!”

The three pairs of heads turned towards the window in unison. The yellow pegasus still hadn’t moved from her spot. Her short pink mane danced in the gentle breeze. Feathers on her wings bristled. She twitched slightly, and for a moment Twilight was sure Fluttershy knew she was being watched, and maybe she might turn around to face them all. But she stayed there, unmoving, watching the sunset. She’d walked to the spot and sat down the moment Wonderbird Two had landed back at the island.

Twilight took a deep breath, and turned to Applejack. “Right. First thing’s first. How is Wonderbird Four?”

“Beat up purdy bad,” Applejack replied. “Missin’ half a control fin, port side’s got a wicked dent in it. Few broken lights, and her belly got scratched up somethin’ fierce. Ah’ reckon ‘bout a weeks work to get her pristine again.”

“We can handle that,” Twilight said with a nod. “We’ll start in the morning. Dash, did you get any word on if the Navy will be able to clear any theramine spillage?”

“Yeah, actually. North Star radioed me to explain just after I left. Turns out the owners of Deepsea Echo were on board the Seaquestria. The lab was running a whole bunch of legit experiments for the UNEQ, they think the theramine was a side project by a few rogue scientists. It being a private company financing a military operation, the chain of command was just a mess. That’s probably why Jetstream wasn’t sure how much she could tell me.”

“Too many cooks?” Applejack asked with a grin.

”Something like that,” Rainbow Dash laughed. “The Navy put a cordon on the area, and the company that owns… well, owned the lab are deploying special sweeping drones to clean the whole area. It’s gonna be a big operation, but it looks like they’re gonna sink all the money they can into it.”

“Good. And most importantly… tell me about Fluttershy.”

“Erm…” Applejack bit her lip, eyes darting towards the window. “Not good. She’s shaken up real bad, Twi. I gave her a full scan when we were flyin’ back, ‘mah ships computer reckons she ain’t seriously hurt. Bumps ‘n bruises mostly, ‘specially on her chest ‘n shoulders. Big impact, her safety harness kept her safe but it dug in purdy bad.”

“But we saw what happened down there,” Rainbow Dash added. “I was scared out of my mind just watching. Can’t imagine how she must feel right now. It’s nothing like the Fluttershy I grew up with could have dealt with.”

Twilight felt her eyes glisten as she looked over to Fluttershy again. “Because she’s not the pony you grew up with,” she pointed out. “This Fluttershy has been through so much more and come out stronger. And she’ll do so again.”

“’Ah reckon so too.”

“How?”

“Because of us,” Twilight explained. “We give her time, we give her space to come to terms with what she’s been through. We offer her all of our support while she processes things. If she needs it, we’ll arrange for some further help for her. You should know, Dash, mental trauma can require as much nurturing as physical trauma.”

Rainbow Dash didn’t respond. Instead she looked back over her shoulders. Where, for most of her life, her wings had been. The things that gave meaning to her existence. Her links to her love and livelihood. Now instead, only a pair of long scars hidden by her fur.

“We’ll look after her, Twi,” Applejack said, breaking the silence.

Twilight nodded. “She knows we’re here for her. We always have been and always will be. Now, you two have had a long day. Spike should have dinner ready soon, you go and get yourselves fed, okay?”

“What about you?” Rainbow Dash asked, as she and Applejack rose to their hooves.

“You are dismissed,” Twilight said, a smile creasing the edge of her lips as she exercised a privilege she rarely allowed herself: pulling rank.

She turned back towards the window as Rainbow Dash and Applejack made their way in the direction of the kitchen. While Fluttershy had still yet to move from her spot, Twilight could see distinctly her posture had relaxed slightly. The tension had ebbed away from her shoulders. She sat with her legs spread slightly further apart. Her spine wasn’t arched so rigidly any more. Fluttershy could be permitted a further period of solitude.

With a deep sigh, Twilight sat on her own haunches. Days like this she questioned the morality of asking her friends to endanger themselves to attempt to save the lives of other ponies. The number of lives they’d saved by this point was staggering, and they’d all given up counting. But each of them had paid a price in their own way, taken their own trauma. Rainbow Dash, Applejack, Pinkie Pie and Rarity. Each of them had gone through their own agonies, but still made it out the other side without any waver in their commitment. They were, despite everything, volunteers.

Today, Fluttershy had defied her own morals, her very nature. To save a small group of ponies who had dabbled in an evil science project that brought pain and destruction down on their heads. The UNEQ courts would see them punished appropriately. But the damage their actions had inflicted on Fluttershy could not be measured, nor could any punishment do it justice.

Resting a hoof against the glass, Twilight sighed again. Fluttershy raised a hoof of her own to scratch at her nose, her gaze still unwaveringly focused on the horizon beyond. Soon, the sun would set. But it would rise again. Wonderbird Four was damaged, but it could be fixed. Fluttershy had walked into a nightmare, and emerged the other side. Yes, she had emerged with a great weight on her heart. But Twilight knew that with the friends she had, Fluttershy would never have to carry that weight alone.

Author's Note

This story was inspired by the original Thunderbirds episode 'Attack of the Alligators!' and by the novel 'The Trench' written by Steve Alten.