“You two probably still have a large amount of questions, if my assumptions hit the mark,” Blink began, stooped over the central dais. “I'm prepared to answer what you might want to know, now that it's pretty much just us. I know I gave you a pretty good overview of the city back on the surface, but, well, there's some other stuff to address, so go ahead.”

Rarity was first to speak. “Well, I suppose my first question would be, ah...what does everything in here do, exactly? It all looks so confusing, a little explanation could go quite a way in helping prevent misunderstandings and, er...fear.” Applejack shot her a look, but she just shrugged.

Blink nodded in response, indicating the troughs over by the wall, connected to the pipes leading into the ceiling. “It's similar to the system we have back at the city—seawater is piped in through the filters to eliminate sediment and other crud we don't want in our drinking water, then it's isolated into boiling partitions, boiled until it's fresh, then piped down into the troughs. Usually, you don't want to drink it when it first comes out—it's seriously hot, but it generally cools quickly. In-craft air circulation keeps it from getting too hot, and if need isn't high for drinking water, you can use it to bathe, as well.

“The control panel's under my jurisdiction, so there's no need to explain that in much detail. It just controls the direction of the craft, helps to jettison ballast if necessary, vents steam and so on. I learned how to pilot them a while ago.”

Immediately, a red flag sprung up in Applejack's head. “Blink...you said you were raised Shetland, didn't you? I remember that pretty clear. You said you left the city really young and grew up around there.”

Rarity raised an eyebrow. “Yes, I remember something similar. You were saying that you only remembered the smallest parts of growing up in this underwater city. How in the world could you have been taught to pilot such a complex vessel at such a young age?”

A flicker of fury crossed Blink's face, but he recovered quickly. “We're going over specifications and functions of the bathysphere, correct? Or did I miss a big—and might I add, unnecessary—shift in the conversation? Because you two asked me about the bathysphere.” There was a moment of silence, and the straight-faced Blink continued.

“Okay, so, that's pretty much the water-filter system and the control panel out of the way, yeah?” He waited for them to cautiously nod before continuing. “Alright, well, the center dais here is mostly just for eating and lighting, plus it connects to the roots of the steam-powered electrical hub in the butt of the vessel. Or the bottom, rather.

“Each one of these things comes stocked with a supply of food, so that's not really a concern. It's over in the hollow beneath the shelving.” He pointed to a set of brass-colored shelves off to the side of the control panel, with a large space in the bottom. The shelves weren't stocked, but if Blink said there was food in the drawer, there probably would be.

“That's pretty much all there is to this old thing, actually. It's a simple vessel made for relatively long-range travel from shore to shore. Even now, it's going to take another three hours to get where we're going. Then it's going to be another four hours from the opposite end to the shores of Equestria—these things are fast, but not super fast.”

Rarity spoke up. “Blink, is there anywhere to sleep aboard this vessel? I find it hard to believe no one sleeps during these trips, especially if they are made regularly.”

Blink shook his head. “In order, yes, there are bunks off to the left of the control panel, in that little room there, and no, these trips aren't made very regularly. It's like I told you before—while it may seem strange to you, ponies actually quite like it down in the city, and they're not inclined to leave without a good reason. The reason these vessels have bunks is, well...I'm not sure. They weren't here initially. I mean, I know, maybe sometimes ponies get on here sleep-deprived or they get bored or whatever, but bunks weren't part of the vessel's necessary design, and it took forever to get the others to see that—and now I see they've ignored me anyway.” Blink had started worrying a lock of his hair with his mouth, looking agitated, even angry.

Rarity raised an eyebrow. “That doesn't exactly sound like something a casual observer would say, Blink,” she said, “especially not one presumably un-involved with the construction or design...Not to sound like I'm trying to needle you, of course.”

Blink heaved a heavy sigh through his teeth, bent over the central dais with his head bowed. “It doesn't, does it? Well, that's because I was aware of the design—they were just making the bathyspheres when I was leaving and, uh, even as a kid I never really liked the design, you know?”

Applejack frowned. “That's...a pretty weak way to dodge the question, Blink. I gotta be honest with you—you're coming off as more shady than a sidewinder in a bag of weasels right now.”

The diminutive stallion responded by straightening up and glaring the pair in the eyes. “I don't go around asking the both of you about your painful secrets, do I?” His voice suddenly spiked in pitch, and his eyes were alight with cold fury, the kind neither Applejack nor Rarity had seen before. “Am I missing something here? Was this 'explain the vessel' or 'grill Screwjack for secrets because we're just a pair of curious fillies on the inside'? You've asked me plenty of times about my past, and I told you about the city I came from, so just...” he trailed off when he saw the both of them staring at him, noticing he'd spat out a different name in his emotional panic. His jaw moved uselessly, working as he tried to find the words to explain himself.

“Blink, uh...” Applejack was struggling nearly as much as he was, it seemed. “Who are you? I mean, really, just who are we sitting in this weird ship with?”

Blink looked like he was about to burst into tears, swallowing constantly to hold back a surge of emotion. “Yes, well, it's obvious I've never been entirely honest with you, isn't it?” he said, looking toward the porthole, “You could only point out the inconsistencies for so long.” He raised his head, looking far-away. “It's not like I haven't seen the both of you wondering to yourselves just who I was. And besides that, well...I already promised you that we'd talk for real. It's past due I did that anyway.” He grinned and dipped his head once more. “To tell you the truth, I'm just upset they modified my design after all. I told them bunks weren't necessary to the design, that they couldn't make the trip in an hour if they built in extra space for the bunks.” He let out one last, wistful sigh and straightened up.

“Let's start with names. To begin with, my name isn't Blink. It's Screwjack Littlebang, of the Littlebang family of famous inventors.” His smile seemed more confident and genuine now. “I know, you haven't heard of us before. We're only really famous down in the city. I'm the lead designer of this vessel, as well as the head engineer for a few of Fizz's personal projects.”

Rarity and Applejack were completely dumbstuck—how could this pony have been lying to them this entire time, and more importantly, how had they allowed themselves to be suckered in by it? Granted, he'd come across as twitchy and suspicious for the most part during their short friendship, but something like this? It was beyond imagination.

Screwjack smiled gently at them, eyes half-lidded. “Like I said before, I'm sure you two have a lot of questions for me. I'm pretty sure I've explained everything adequately enough about the workings of this vessel.” He swept some of his hair from his eyes—they had a watery quality to them that hadn't seemed present before. “You're free to ask me anything you want, and I'll be willing to answer, now that proper introductions are out of the way.”

Rarity was the first to find her composure, trying to control the millions of thoughts rushing through her mind. “Blink, er, Screwjack, why the deception? Why would you lie to two ponies who were not only willing to put their lives on the line for you and your surrogate family, but willing to travel with you to some underwater city they know nothing about? I won't lie to you, I feel betrayed and very hurt.”

Screwjack nodded, looking pained. “I didn't really want to have to do that, but...did Glow Star ever end up telling you the story of that weather-controlling pony with 'ticking legs' and mechanical wings?” Rarity nodded. “That would be why. I don't trust the surface not to be riddled with spies, especially if ponies like him are cropping up and making threats. As much as I would've liked to blow Star's mind with the knowledge of who I really am, I can't trust that information like that doesn't come out, whether by force or accident. I know how I was acting there and, well...things like this can make anypony irrational. I wanted to tell you, then I didn't, then I did and, well...my whole mind is a mess, despite how I might seem.”

Neither pony had, in truth, followed most of what he'd been saying, especially considering the best they'd currently done on the surface was lighting. However, they also both realized that it was probably better to just go with the flow, for now. They'd only be visiting the underwater city for a short time, so the information had a pretty short shelf life anyway.

“So,” Applejack said after a long, tense silence, “you designed this uh, thing here? It's pretty impressive!”

Screwjack nodded. “Yeah, that I did. Or, well, me and a team of other engineers who...” he trailed off, seeing confusion starting to rise in their expressions. “...yeah, I designed it, along with a few others. Not really my best work—mostly because nopony was willing to listen to me after a point.”

Rarity raised an eyebrow. “But you seem so on top of things. At the very least, you seemed to understand at a glance what was er...“inefficient” in here. Especially considering they may have updated things since the last time you were down there.”

Screwjack shook his head. “Somepony with a basic mechanical understanding could figure out that the shelf space and the bunking is unnecessary, given the length of the voyage from point A to point B, and especially when you figure in that the vessel would travel faster without the extra space and weight.” He clenched a hoof. “But no, we've got to have bunking, after all, what about when children are sent on these voyages? A foal is just as capable of sleeping in their mother's arms as they are sleeping in a bed if it's only three hours!” He slammed a hoof on the center dais for emphasis. “We increase the length of the trip and sacrifice efficiency for comfort, but of course, can't have the whole two ponies who have ever used the system getting cramped from the lack of space, now.” He was huffing and puffing by the time his rant tapered off, and he ran a hoof through his mane.

“Sorry about that. It's just very...aggravating to see that they deviated from my design so much, even after I told them that the way I was plotting it would allow for more trips with less hassle, to make no mention of the decreased water usage.”

Applejack had gotten completely lost, but still managed to find words. “Well, uh...I'm sure your plan or whatever was good, but would something that small really make you leave? Seems like kind of a silly thing to leave your home over.”

Rarity nodded. “Yes, I was wondering the same thing. Are you always this passionate and spirited about projects you've worked on, or is this special? I can speak from experience when I say that certain projects always seem to get under one's skin more than others, more so when time investment increases.”

Screwjack once more shook his head. “It wasn't the bathysphere design, that was after I'd already made arrangements to leave. They asked me to consult on this since, after all, I was going to be leaving in it. However, when I was sent off, a good eight or nine months after the start of the project, I left in a sphere that I'd designed. This,” he scoffed angrily and waved a hoof around, “is a change they made after I left. I wanted to leave in the first place because of the Shatterback rigging and the Flow Manipulator I made for Fizz.”

Rarity chimed in at this. “Fizz? He's the one who runs the city, correct? I remember you saying that he'd gone out of his way to turn himself into a clanking, whizzing, mechanical alicorn. That he'd spent days in the darkness of his lab, making modifications to himself unbeknownst to the residents.”

“That's true,” Screwjack said, looking far away, “but I never told you he was alone. Look, my family has been making things for Fizz for a long, long time. I'm talking back when this first got started and my ancestors were helping him haul mortar, brass and rivets onto the sea floor. It figured that, as a member of the Littlebangs, I would invent something to help the city, and something to help Fizz. It's practically the natural order for my family.

“My main contributions, however, were nearly all for Fizz, and it wasn't until I saw the end result that I realized what I did was wrong. Well...wrong is an easy word for it. Too soft, but there probably isn't a word in any language that can describe how I felt about it.”

Applejack's face twisted. “That doesn't sound good. I mean, I've done some powerful bad things in the past, but nothing I couldn't eventually forgive myself for.”

Screwjack's eyes flickered bitterly. “I don't think forgiveness exists for ponies like me. The Shatterback and Flow Manipulator were by far the greatest mistakes of my life. Even after I'd made them, something in my gut told me I'd committed a great atrocity.” He looked up through his curtain of hair, eyes glassy. “I put too much power into the hooves of a single pony.”

“But Screwjack,” Rarity said, “what are those? What exactly do they do?” Just then, a whizzing and beeping sounded off from the forward panel.

Screwjack's ears twitched and his head snapped to look at the console. “...I guess I'll have to tell you later,” he responded, “or never, if you're lucky.” He trotted over to the panel, turning a few knobs. “I know this is a lot for you handle, especially given the situation you're currently walking into, but I figured with how good the both of you have been to me, and to the Shetlands I came to treasure, you deserved at least some of the truth.” A whir started up on the console, and Screwjack immediately silenced it. He opened his mouth to say something, but was cut off by a gasp of wonder emanating from Rarity, who was glued to the porthole.

As the bathysphere crested a ridge of colorful coral, the city made itself known. It was quite close now, and it seemed that the rest of the journey offered an unobstructed view of it. To Rarity, at least, it was absolutely gorgeous.

The entire place was lit up like Canterlot on Hearth's Warming Eve, a rich gold penetrating through layers of navy blue and black. Long arcs of light cut through every inch of blackness, leaving not a single place without the warm and inviting glow of light. Even from this distance, and through the dirty porthole, Rarity could feel her heart swell at the sight of genuine civilization, and though Applejack asked her if she, too, could get a look, Rarity could hardly hear her.

Massive brass spires erupted from the ground nearly everywhere Rarity could see, the tops spiraling and ridged. The metal was remarkably well-preserved—an extremely thick, clear dome was built over the city, Screwjack explained, and was only open at a few points to pipe in seawater to be purified for farming, powering engines, and other uses, as well as two points for sphere-travel. Now that she was looking for it, Rarity could see the points of light dancing on the edges of the sphere, shimmering and swaying with every inch the vessel moved.

This was all accompanied by a distant drone—the sound of seawater being drained into the city—which made the spectacle look and feel more like a dream than anything. Even parts of the dome, Rarity could see, were decorated, painted on. It was like seeing the world's biggest, underwater festive tree. Applejack hadn't thought quite as much of it, offering up a few choice words like “unnatural” and “ugly”, but Rarity couldn't have cared if she tried.

The whole experience filled her heart to the bursting point, and tears were welling in her eyes. “Screwjack!” she cried, “You hadn't told me it was so beautiful! I'd been expecting something impressive, but this is far beyond that!”

The earth pony shrugged. “I guess I've gotten used to it. When you've seen it from the inside as much as I have, you start being less impressed by it on the outside. Granted, I saw it from the outside a lot, too, when I was working on the spheres. Besides, you'll probably be less stupefied once we're inside and hurrying to the other sphere.”

Rarity frowned. “But there must be so much to do and see! Why must we rush through?”

Now it was Applejack's turn to frown. “Rarity, come on now! Did you forget what we're even trying to do?” She trotted over to the unicorn. “We're supposed to be getting back to Twilight and the others, remember? Our friends, the ones we haven't seen in weeks, who we're powerful eager to get back to?”

Rarity faltered for a moment, then bit her lip, looking like an embarrassed filly. “Ah, yes,” she said, looking away, “my apologies. I suppose I simply got caught up in the excitement of seeing something that isn't blue, green or brown for the first time in several weeks. I lost myself there for a moment.”

She gave AJ a bashful smile, which prompted a scoff and a good-natured shove. “See, this is why I'm around. So somepony can keep you on the straight and narrow and make sure you don't go runnin' off to get, I dunno, metal hair or something.”

Rarity tried to look serious, but couldn't hide a smile. “Oh yes, metal hair, that's in season. No treatments to make my skin and coat tighter and shinier, nothing for my untamed hoof-locks, no grooming of my tail, the very first thing I would do is run off when you're not looking and get metal hair. While I'm at it, I may as well get a metal stomach to hide my scar.”

Applejack was now failing to bite back a giggle-fit as well. “Yeah, sure,” she said, “just don't go coloring it wrong—your belly's yellow enough.”

Rarity huffed. “Oh, you're just impossible! You-” A throat-clearing from Screwjack cut her off as yellow light poured in through the porthole.

“Uh, lovebirds?” A loud, metallic clanking and whizzing filled the air, as well as a rush of water. “We're here.”

Author's Note

Alright, well, I went ahead and put this together over several days. This is a reveal I had planned more or less from the beginning, so it's nice to get it out there. Hopefully the next few chapters will be lighter on the exposition, but I do have a city to build, I suppose. Thanks for sticking around, anyone who reads this, and thanks for having faith this would continue.

EDIT: Changed the dialogue formatting in certain areas for the sake of clarity, and while past parts likely won't receive the same edits, I'll try to keep this formatting style for the future. I also made a couple other small edits for the sake of clarity and flow.