Shetlock watched while the three humans boarded the chariot, the bipeds all remaining quiet and shuffling along without much energy.

He noticed that Simon still held onto the simple black briefcase, the leader being the last one to enter the heavily guarded chariot. Sighing, Shetlock turned away from the library window and gathered up his notes.

“They’ll be safe,” Princess Sparkle told him, getting up from her chair. “Princess Celestia will make sure that nothing happens to them, then we can stop this.”

“I know, I just can’t shake the feeling that something’s wrong,” he explained. He finished putting his notepad and pencil in his vest pocket, before he turned for the door. “This case isn’t over, not by a long shot.”

Without waiting for a reply, he passed to two door guards and emerged into the moonlit streets. The flapping of wings drew his attention to the road in front of the library, the chariot carrying the humans flying into the night sky with a swarm of pegasi guards surrounding it. Spotting Major Bastion and, surprisingly, Lieutenant Strike standing by a waiting chariot, Shetlock headed towards them.

He nodded a greeting to Bastion before tilting his head at Strike.

“Lieutenant, out of hospital so soon?”

“It’s not that bad,” Strike mumbled out, his nose still tightly bandaged. “My vision is still a little blurry and my ears are still ringing, but I’m okay to travel. Besides, if I have to return to Canterlot then I might as well catch a ride with you and the Major.”

“Don’t worry about Strike, Shetlock,” Bastion reassured. “We guards are hardier than we look. I take it that you’re ready to leave?”

“I am,” Shetlock answered, stepping towards the chariot’s open door.

“Good, if we leave now we should be able to catch up to the humans and land at the same time. The town has been blocked off and nothing is getting out now, the killer is trapped.”

Looking up, Shetlock noticed three pegasi fly overhead, the guards scanning the streets below them. “I just hope we can find out what we need to stop them,” he stated, Bastion stepping into the chariot.

“The same goes for me.” Bastion made room for Strike who followed him in, leaving Shetlock for last. “If this case collapses, then I’m the one who’s going to be reporting failure to the Princesses.”

Without much more to add, Shetlock climbed in after them. He sat down on the plain blue cushion of the guard transport, opposite the two guards. Guards outside the windows strapped themselves into the front of the chariot, and with a few flaps of their wings they pulled the chariot into the sky. Taking a second to once again admire the view from the sky, Shetlock’s gut churned when he focused on the town below them.

It would never be the same sleepy hamlet, not after what had happened. Briefly, he wondered how the inhabitants would cope before he gave up and levitated his notebook from his vest pocket. Flicking it open, he went over what information they knew.

The killer was likely a trained soldier of sorts, and had already displayed a twisted sort of enjoyment from their acts. Going off the voice that the guards had heard in the inn, they were positive that the suspect was male and a young adult. The mare in the alley, Mellow, had confirmed that the killer was a biped and so it was indeed a human. The suspect wasn’t afraid of the guards and seemed willing to inflict harm upon ponies as well, probably the most disturbing revelation.

“Shetlock, give yourself some rest.” He looked up, Bastion gesturing towards the windows. “We’ve had a stressful night, and we’ll be in Canterlot before the hour. Put down that notebook and grab some sleep, I think we’re going to need it.”

He was just about to protest, before he considered the advice. Sleep did sound good, even if it was only going to be a short nap. Hesitantly, Shetlock placed his notebook back in his vest pocket and leaned his head against the white wall of the chariot. As he felt his eyes start to droop, he was still surprised that he was even able to get to sleep at all, after seeing the things that he had.

“Shetlock, wake up.”

With a snort, Shetlock was greeted with a ton of noise and movement. Blinking his eyes open, he looked around. He was still in the chariot, Lieutenant Strike exiting it while Bastion was smiling at him.

“Did you have a nice nap?”

“It was dreamless,” he replied, thankful for that fact. He stretched his legs and looked out of the windows, a mass of guards surrounding a chariot next to them. Recognising it as the one that the humans were riding in, Shetlock got to his hooves and checked that everything was still in his pockets. Following Bastion out of the transport, his hooves clattered down onto the cobbled road.

They seemed to have landed in a city square, almost right next to the castle. That was a blessing, the closer they were to safety the better it was for everyone. He joined Bastion and Strike, the two guards watching over the unloading of the second chariot.

“Made it safe and sound,” Bastion observed. “Once the humans are secure, I’ll be heading back to organise the search in Ponyville.”
“I’ll stay here to question them, hopefully we can gain more of an idea about what we’re facing.”

“That would be most appreciated,” Bastion replied, giving Shetlock a grin. “By the way, expect your Chief to hear very good things about you, Detective.”

“Thank you sir,” Shetlock acknowledged. “However, I’d prefer you to hold your praise until this case is over and we haven’t got a killer to worry about.”

“I can do that.”

A scuffle over at the second chariot drew their attention, Bastion and Strike flicking their wings towards their swords at the noise of raised voices. With urgency, the three rushed over to the circle of guards, a stream approaching them from the castle. Upon getting closer, Shetlock could make out the angry words being exchanged.

“I don’t care what your Major ordered; you can’t just land next to the castle and expect entry straight away!”

“Listen here, bat-pony, we have orders from the Princess herself to escort these creatures to her at once, and to ensure their safety! To Tartarus with your rank and protocols!”

“I haven’t received anything from Princess Luna regarding any creatures, so you’ll just have to deal with it!”

“Princess Celestia herself permitted us entry, and Major Bastion has explicit orders to-“

“Well then, Sergeant, I don’t see this ‘Major Bastion’ around anywhere!”

“Actually, I’m right here.”

Shetlock followed Bastion while the Major pushed through the crowd. Now able to see, Shetlock noticed ten Lunar guards squaring off with the sixteen pegasi that had been pulling and guarding the humans’ chariot. Bastion trotted up to the leader, the bat-pony with a larger plume in his helmet, and stared down the other guard.

“Major Bastion?” the bat-pony glared, Bastion nodding his head. “Care to tell me why your guards are trying to enter the castle with unknown creatures in the middle of the night?”

“As my subordinate has already stated,” Bastion started to explain. “Princess Celestia has ordered us to escort the three humans to her, direct from Ponyville.” The bat-pony seemed to pale at the mention of the town. “I take it that you have been made aware of the situation?”

“I… I have,” the Lunar guard replied, his prior bluster gone. “So they are…?”

“The survivors,” Bastion confirmed.

“I still need to check it out,” the Lunar guard apologised, now much more civil. “Regulations, and we don’t know if you’ve brought the… problem with you.”

“We haven’t,” Bastion told him. “The town was sealed off before we left tonight.”

“I still have to check, now tell your guards to stand aside.”

Shetlock watched on while Bastion continued to gaze at the bat-pony, before the Major raised a hoof. “Everypony, stand down and allow them access.”

The pegasi all parted, spears still at the ready while the bat-ponies advanced on the chariot. The night guards investigated every bit of the transport, their leader opening the door and talking to the occupants inside. He stepped to the side, the humans and a unicorn exiting.

“Guard, over to the left,” a bat-pony ordered. The unicorn, tasked with shielding the humans, glanced towards Bastion. After a nod from the Major, he complied with the order and joined his fellow soldiers on the sidelines. The bat-pony leader inspected the inside of the chariot while his subordinates examined the humans and asked them short questions regarding their intentions.

All in all, it seemed rather petty to Shetlock, but he guessed that the guards just worked differently. The obvious rivalry wasn’t helping, the guards all tense and watching each other instead of the perimeter. Bored with observing the bureaucracy of the military, Shetlock instead took the time to examine the city around him.

He’d only ever been to Canterlot once before, and that was when he was a young colt with his parents. Now, looking over the elaborate buildings and the magnificent castle, he made a note to take them both out to lunch after the case. While the two tailors didn’t share his passion for crime-fighting, in fact they had told him that the thought of him in danger daily scared them, he still saw them once a week.
Scanning over the golden spires of the castle, he smiled to himself. It would certainly be nice, a relaxing meal in the wonderful capitol.

Focused on his thoughts of what that day would be like, Shetlock almost missed the small glint that he noticed coming from the top of a distant castle spire.

‘What was that?’ he mused, squinting his eyes. It flashed again, far from any gold that could have caused it.

“Are we done?”

He turned back to the humans when Simon asked the question, the bat-pony leader stepping around them a final time.

“While I don’t like you carrying weapons, no matter how blunt they are, I suppose that it’s okay as long as you remain with your escort at all times.”

“Trust me,” Simon answered the bat-pony emotionlessly. “We have no intention of going anywhere without them. We just want to get into the castle.”

“Go ahead.”

“Okay ponies, let’s get moving,” Bastion ordered, the pegasi forming up into an ordered square around the humans. The lone unicorn joined the three bipeds in the centre, Shetlock turning to look for a final time at the tower that the glint had come from. “Shetlock, we’re heading into the castle.”

“Wait,” he told them, Bastion halting the troops and walking up to join him.

“What is it?”

“I saw something on that tower,” Shetlock told him, pointing a hoof towards the spire in question. “Like the moonlight glinting off something.”

“A glint?” Simon questioned from the square, Shetlock and Bastion turning just in time to see the human’s eyes go wide. “Sniper!”
Just as he cried out, all three humans dived for the ground. For the confused Shetlock, time seemed to slow down. Harriet and Aries hugged the ground, their weapons still hidden in their cloaks.

Simon, however, was too slow.

The oldest human went to shield the briefcase he held with his body as he dived, but as soon as he moved something hit him. Shetlock could do nothing but watch in horror while a hole the size of his head was punched into Simon’s chest, a spray of blood flying out for meters to cover the guards behind the human. Simon’s eyes went wide, Shetlock and Bastion dashing forward towards him as Simon’s body hit the cobbled road with a thump.

It was chaos, the unicorn’s shield went up, pegasi ducked for cover, bat-ponies scattered and tried to avoid the same fate.

“Simon!” Shetlock and Bastion reached Simon just as Harriet and Aries did, the two humans crouching over their fallen comrade. “Simon, come on, you can’t die!”

Looking down, Shetlock could see that the dying human was not long for the world. The hole in his chest was losing blood fast, a third of the torso torn out thanks to the hole. He could see flesh, muscle and bone while blood weakly dribbled out. Harriet was sobbing over him, while Aries was shaking uncontrollably.

He couldn’t do anything, nor think of anything to say while Simon bled out. One of his hands was clasped around the handle of the briefcase, while the other was firmly gripping Harriet’s. Simon raised his head, the human’s eyes wide. Harriet looked into the eyes, Simon looking like he was about to say something.

A weak gurgle and a trickle of blood escaped his mouth, before the light in his warm eyes died out and his body went slack.
Shetlock stared down while the hand holding Harriet’s let go, the briefcase held in the other dropping to the road. The sounds of more guards approaching didn’t register with him; neither did the bellowed orders from Bastion telling to bat-ponies to search the castle for the human. He didn’t even react when Lieutenant Strike pulled him away, leading him into the castle past the streams of guards that were far too late to be of any help.

Shetlock continued to sit on the stone step while guards rushed past him.

He couldn’t focus, the sheer shock of Simon’s death flooring him. Sure, humans had died before and he had seen the scenes, but this time he had actually seen the one who he had talked to multiple times die right in front of him. Shetlock couldn’t work out why; their plan had gone perfectly up until then.

They had escaped Ponyville and had blocked off the town, it was impossible for the killer to follow them once they had left. He questioned whether Simon would have made it if they hadn’t been stopped by the bat-ponies, if that had somehow given the killer time to take yet another life. Once again, the murderer shouldn’t even have been in Canterlot, it was like they had somehow know the plan and had beaten them to the city.

He raised his head from his forehooves when guards rushed past him through the main gate, shields up and heads raised to scour the towers for any sign of activity. Spears and swords were drawn, more guards rushing out to meet them from the castle itself. Hastily-armoured Solar guards, alert Luna guards, all began to search for the intruder. Spotting Bastion in the crowd, Shetlock got up to join him, guards letting him through without complaint.

Closing in, Shetlock could see that Harriet and Aries were with Bastion, Aries clutching the briefcase to his chest while Harriet swept the rooftops with her weapon sights and a pained glare. A shimmering shield was covering them, the unicorn in the centre making sure to stay right next to the pair. Trotting next to Bastion, Shetlock accompanied them while they headed through the open courtyard.
“Major, what is going on?”

At the voice, everypony looked up.

Celestia herself flew down from the throne room window, four more pegasi guards with her. The sun princess had a stern look on her face, her guards peering around the area. Her golden-clad hooves hit the path, the Major not bowing but ushering her along.

“There is no time, Princess,” he explained while herding the humans along. “We’re under attack; the killer is inside of the castle!”
Celestia acted within seconds, a yellow shield covering them all when her horn glowed. Under the golden dome, Shetlock felt his heart rate return to normal and his breathing slow. Taking a deep breath, the fear he held bleed away to be replaced with a calming warmth. Celestia wasted no time in approaching Harriet and Aries, her wings spread.”

“Princess!” Strike tried to warn, but it was too late.

Celestia enveloped Harriet and Aries in a hug with her wings, moving with them until they had entered the main doors to the castle. She only let go and dropped her shield when the heavy barriers shut behind them, locking out all danger and leaving them safe. In the wake of the surprise embrace was two confused humans, their faces a mixture of sorrow, fear and horror.

“I’m so sorry,” she whispered to them, wiping their tears with her wings. “Is the third-“

“Simon’s dead,” Harriet informed with a sob, Celestia moving to hug them again. All of the guards and Shetlock watched while the Princess comforted the two alien beings, Harriet’s gun held limp in her hands while she cried into Celestia’s wing. Aries merely shook, the human affected permanently by the experience.

“Hush, you’re safe now,” Celestia told them, before raising her head to look at a nearby solar guard. “Captain Arcane, search every inch of the castle and send more pegasi to help Luna and her guards scour the sky, I want the monster who did this found.”

“Yes Princess,” the unicorn answered. “And if we find them?”

“Do what it takes to ensure the threat is gone,” Celestia answered, before turning back to comforting the two beings she held. “There, there, I’ll protect you now.”

“Princess,” Major Bastion spoke up, the stallion visibly shaken. “We should make all hast to the safe room, only then can we rest.”

“A wise idea, Major,” Celestia murmured, before urging the two humans forward. The column of guards, numbering just over forty, moved as a mass down the corridor with Celestia, the humans, Major Bastion, and himself in the centre. Looking around, Shetlock assumed that Strike had left to help the other pegasi leaving only unicorn guards behind. Horns lit up and swords sat waiting in their scabbards, ponies checking every corridor that they passed.

They moved deeper and deeper into the castle, the safe room located underground was their destination. Shetlock didn’t know what it was, but he assumed that it was usually reserved for the Princesses and important nobles during times of war. During the walk, Harriet had moved out of Celestia’s hold to walk at the back of the centre group, looking behind them while keeping her weapon trained on any corridor.

Just as they turned the corner to enter a new corridor, a commotion came from the back guards. Celestia halted halfway down a long flight of stairs, the humans and accompanying guards also pausing to turn around. Shetlock found himself pushed to the left side, guards parting to allow a single pony through.

He winced when he noticed that the earth pony maid was bleeding heavily from a gash across her chest, the red staining the pink fur and white apron. Celestia rushed forward with her horn lighting up, but the maid waved a foreleg to stop her.

“Princess,” she huffed out, dropping her feather duster to the ground. “Something attacked me in the last corridor; the monster is on its way after me!”

Guards snapped into action without having to be ordered, the ones at the bottom of the staircase rushing up to put themselves between the VIPs and the oncoming threat. Shetlock found himself, the humans, Celestia and the injured maid pushed to the back, the guards all lowering their weapons in preparation to meet the attack. Shields flickered into life to cover them all, and he braced himself when the sounds of shouts and massed hoofsteps approached.

Spears were thrust out but hit nothing, another twenty guards skidding to a halt when they rounded the corner. The two groups stared at each other, before confused muttering broke out between them all.

“It was right here, we were right on its tail!”

“What do you mean? We’re waiting for it now!”

Shetlock however, was focused on a far more urgent matter.

‘Wait… why is there a maid down here at this time of night?’

Just as he figured it out, a chilling voice sounded from behind him.

“Oh, I also have a message for you, Harriet Snyder and Aries Brinstone. Was it all worth it?”

Shetlock whirled around with Celestia, Bastion and the rest of the guards, just in time to see the injured maid stand on her hind legs in front of the frozen Harriet. The human went to fire her gun, but with a supernatural speed the maid struck out with a hoof.

The hoof made contact with Harriet’s chest before Shetlock could even blink, Aries scrambling back towards the guards in horror.
Harriet swayed on her feet before the ‘maid’ withdrew the hoof, a thin blade emerging from the bottom of her hoof withdrawing with a faint coat of blood on it. Once again unable to do anything, Shetlock stared while Harriet dropped to her knees and then fell face-down onto the floor, the killer dropping back onto four hooves.

“Monster!” Celestia shouted, rage and sadness mixing in her tone. She lowered her horn towards the grinning maid and spread her wings, hiding Aries behind her while the guards shifted to counter the new threat. Shetlock once again found himself shoved back behind Bastion, the fuming Major levelling his sword towards the murder.

“A pony!?” Bastion yelled, Shetlock sharing his confusion.

That confusion turned to utter fear when the maid looked straight at him, her blue eyes flashing a menacing red.

“Well, not quite.”

A blue flash surrounded her form, causing them all to turn their heads away. When he looked back, Shetlock’s heart sank when his eyes landed on the familiar tan mare in front of them, facing the spears with a smile on her face.

“...Mellow?”

“Actually Shetlock,” she replied while raising her eyebrows at him. “My correct name is Unit One, and the ISA sends its regards.”

Author's Note

For those who don't know who Unit One is, it'll will be covered next chapter when we get to see the story through her eyes.

For those who are familiar with that obscure one-shot featuring her... yeah, it's happened. A reader requested more Unit One, I thought that a perfect setting would be a crime/dark.

Expect next chapter to 'fill in all the blanks,' so to speak, but if you look back over the fic you can probably spot the hints alluding to 'Mellow's' part in all of this.