The first thing Rainbow noticed when she stepped out of the stairwell was the smell. Throughout a faint haze of rubbing alcohol and lemon, there was also a worrying scent of iron and bile.
She had figured that the actual laboratories would be white walls, white floors and bright white lights. What she saw instead was something more akin to an abandoned asylum. Dingy, gray concrete before her lined the cracked black-and-white tile floors, while dim, rectangular fluorescent lights above only adequately lit the area. Cobwebs hung from the black domes up above, and small piles of rubbish laid in the corners of the halls, meticulously designed to be just as labyrinthine as the floor above. A cart covered in vials, syringes and used surgical tools was rolled to the far left, still slick with blood. The dark grey cloud walls to her sides were no longer there, but she assumed they were still surrounding the walls of this dangerous, demonic building.
"Ack! They actually do science in a place like this?!" Twilight cringed. "So many health code violations!"
"To hay with the health code!" Rainbow argued, incredulous. "Ponies are being experimented on here and that's what you have a problem with?!"
"Of course not!" Twilight exclaimed. "Just... I dunno, trying to 'giggle at the ghosties', I suppose." Rainbow didn't have to look at Twilight twice to see that she was just as unnerved as she was. She let out a sigh.
"Well, if their labs are as filthy as this hallway is, no wonder their prisoner patients die horribly," she grumbled as she began down the left hall. Though their hoofsteps were still muffled, Rainbow grimaced as she felt something sticky yet unseen on the floor. A few more steps down the hall they suddenly heard a distant stallion scream, a grim reminder to be careful.
Though better lit than the holding cells above, the hallways looked much the same as before. Dirty concrete walls smeared with Celestia-knows-what, endless locked metal doors with folders or clipboards laying beside them, powered-off computer stations and filing cabinets locked and warded against opening spells. Every so often a splotch of dried blood or bile broke up the monotony of the tiled floor. Large pieces of various and filthy medical equipment seemed shoved, almost hidden in every spare corner. Some looked normal enough, but others had seemingly tens of needles and scalpel blades poking out of multiple robotic arms, or electrodes connected to a battery the size of a watermelon, or had shackles attached to it.
All the while, Rainbow's mind filled with dread.
They turned a corner. Light shone out from one of the metal doors in the form of a window slid open. Cautiously, Rainbow and Twilight peeked inside.
An Earth pony in a lab coat loomed over another pony lying belly-up on a gurney. His light green fur was almost entirely covered by said coat, and his dusty-blue mane was tied back and stuffed into a hair net. He moved to the right and out of her line of sight, revealing the same Pegasus Rainbow had watched being stabbed with electrified prongs and carried out of the holding cell not even an hour ago. He laid with his head facing the door, and his eyes met hers; Rainbow recoiled slightly in fear of being noticed, but the stallion only blinked. His mouth opened only to drool and gurgle noiselessly. An empty syringe, a scalpel and a device resembling a laser pointer sat on a covered tray on wheels next to the gurney.
"Still trying to beg for leniency, #738? I really can't see why you're so worried, after my little... alteration, you won't feel a thing," The pony in the lab coat chuckled darkly, towing something large into view. Whatever it was, it was in a position that a pony standing on their hind legs could fit, golden-brown in color and mostly hollow inside. However, there were many thin, sharp, barbed spikes attached to the insides, each connected by dozens of wires that all led to one particularly nasty spike, roughly at the same height as the bottom of a standing pony's skull. The Pegasus' eyes strained to look at the thing from his position, his irises nearly disappearing, and he gurgled again.
"Besides, think of the good you'll be doing for all ponies that have lost the ability to fly, or even walk." The pony in the lab coat then picked up the Pegasus, who put up no struggle at all, rather seeming like a lifeless doll. As he swung him around into position, a horizontal slit of red just underneath the back of his head stared like a monster's eye into Rainbow's soul. With little difficulty, he placed the Pegasus carefully into the mysterious contraption. His eyes darted frantically around his newest prison, and his gurgling increased.
"Now, then... let's see how my newest prototype walking apparatus works, shall we?" The Pegasus clenched his eyes shut in terror. The pony in the lab coat moved a hoof behind the contraption. Rainbow heard the soft click of a button being pressed.
Then all she saw was red.
What had been the opposite sides of the contraption's limbs clapped shut, producing a nauseating, squishy crunch from within. Blood splashed, then oozed out of the cracks in great streams. The Pegasus' head, the only part of him still visible, was painted in scarlet liquid. His eyes snapped open and twitched wildly, his pupils were pinpoints, and his mouth contorted into a wordless scream. Bile frothed from his mouth as the pony in the lab coat calmly wrote something down on his clipboard, seemingly oblivious to the Pegasus' fate.
"Hmm... seems as though I didn't cut enough. You felt something, after all. Anyway, onto the first test." The pony in the lab coat grabbed what appeared to be a remote control and began fiddling with the buttons. The contraption shakily moved in response, the Pegasus' eyes glazing over as it took a few tottering steps towards the door. Rainbow watched in abject horror, unable to tear her eyes away, as the final wisps of life left the patient. At that point, the automaton seemed to move much more freely, and the pony in the lab coat set the remote down.
"Aw, #738... and here I was hoping you had so much more vitality in you," he sighed. Looking down at his clipboard for a few moments and filling something in, he then glanced up at the lifeless head, mouth still dripping with blood, bile and drool.
"Hmm... quite unsightly. Let's liven you up a little bit, shall we?" He disappeared to the left for a few moments, returning with another golden-brown part of the contraption. A brief glimpse of the inside revealed many inwards-facing barbed spikes, ensuring it could never be removed once placed. The pony in the lab coat then set the piece atop the Pegasus' head, shoving it down into place and sending more streams of blood down the automaton's body. As he stood back to admire his hoofiwork, Rainbow's breath died in her throat.
He had shoved a bear's head on top of the contraption.
A bear's head wearing a top hat.
The pony in the lab coat began to giggle madly, clearly pleased with himself. He pressed a button on his remote, and the automaton began to laugh as well, producing a wheezing, hollow, haunted, moaning cackle. The pony laughed even harder.
The snacks she had consumed earlier began making their way back up her throat. Rainbow finally pulled herself away from the disgusting sight, dry-heaving as she fell to her knees. As she gagged, Twilight was silent beside her, face frozen in shock.
It took her a few minutes to recover. "G-Gh... why... whywhywhy..."
"I know, Dashie, I know," Twilight soothed, rubbing her back. "We have to keep going, though. He might be finished for the night and leave the room soon." She pushed Rainbow gently down the hall, Rainbow struggling to take the first few steps away until she shook the last of the lingering nausea from her head. It took all of her willpower to not begin running down the halls as fast as she could, away from Twilight, but away from that sight. The Pegasus' blood-covered face haunted her whenever she closed her eyes or even blinked.
She lost track of time as they wandered the halls. At times she heard more screams, airy and distant, echoing through the air ducts. No matter how slowly she walked or breathed, her heart wouldn't stop racing. Her mind screamed at her, why hadn't she taken Twilight's advice? Why hadn't she left and returned with the rest of her friends, or the Wonderbolts, or even Princess Celestia? Then she could have saved them all!
But it was far too late, she was too deep inside to leave now. And leaving and coming back would have only put the rest of her friends and her coworkers-slash-idols in danger. She also wouldn't have been able to save that Pegasus stallion either way.
And poor Spritz.
An image of the filly trapped inside another automaton flashed through her mind. She would have screamed in horror if she hadn't crammed her hoof in her mouth by instinct. Twilight flashed her a terrified look, only looking away when Rainbow's muffled scream ceased.
Finally, after what felt like hours of stealthily tugging at every locked metal door in the maze of hallways, they came upon another one with light coming from inside, across from a computer station. Rainbow carefully peeked inside, spying two ponies in lab coats hunched over a table. Their voices were hushed and unintelligible through the door, but that didn't stop Rainbow and Twilight from watching through the window. Whatever, or whoever they were working on, had a full set of electrodes connected to them, their brainwaves visible on a nearby electroencephalograph. A large tray covered with every conceivable surgical tool, bloody from use, sat at their right side.
They watched in silence for what felt like forever as the two ponies poked and prodded at their patient. At times one would grab an empty syringe in his magic from a cabinet and take a sample. He did this three separate times with no issue, but shortly after the fourth the manicured zigzags on the EEG quickly devolved into chaotic waves of activity, while various machines began a cacophony of beeping. The other grabbed a different syringe from the tray and injected it into the patient, but to no avail; the lines straightened out entirely a few moments later, and the beeping became one solid, grating tone.
Rainbow watched blankly as the ponies seemed to shrug at each other in indifference. Having been in a heightened state of panic the past few hours, she was beginning to feel fatigued. She barely even noticed that the two ponies were in the process of turning around.
"Rainbow!" Twilight hissed as she yanked her down and away from the window. She tried to move but her legs- no, her entire body felt stiff and heavy, so she allowed Twilight to drag her behind the computer station's desk. Shaking the fog from her head, she heard the droning beep suddenly cut off, then what sounded like a running faucet, then a few seconds after it stopped, the metal door opened with a click. Twilight gently shoved her into the desk's chair space, following immediately after as the ponies came closer.
"Well, we got a few good samples, at least. The Overseer should be happy about that."
"I told you you were too close to the hypothalamus! We could've gotten at least two more samples from him!"
"You saw how tiny it was! I'm surprised he lasted as long as he did, honestly."
"Yea, well... let's get these down to Level 2 so we can call it a night, already."
Their hoofsteps indicated they were headed down the hallway and away from them, so Twilight peeked her head out to ensure they were out of sight before motioning to Rainbow. Her eyes widened as she snaked around the desk; they had left the door ajar. Curiously, she swung it open.
She instantly felt sick.
A short, stubby, teal-green Pegasus colt laid face-up on the table. His limbs had been shackled, his underdeveloped wings were tucked beneath his body, and his silver-gray tail laid matted and frayed. A kind face too small for his head stared emotionlessly, lifelessly at the ceiling.
The top of his skull was missing.
His exposed brain had a number of needle electrodes stuck inside the various gyri and sulci of the different lobes. Parts of the lobes had also been removed, taken as samples; straw-colored fluid pooled in a couple of small pockets that had been stirred and mashed deep into the white matter. A thick smell of coagulated fat filled the air.
No... no... nonononononononono-
Nausea smashed into Rainbow like an ocean wave. She flung herself at the closest garbage can, not caring what could possibly be inside. Tears stung her eyes as her stomach emptied itself, the scent of fresh bile and half-digested apple products only making her nausea worse.
Nonononono... Dewdrop... nooooooo...
With nothing left in her digestive system, Rainbow shakily pulled herself up from the garbage can, tears still falling from her eyes. Guilt and despair wracked her entire body, making her feel heavy and slow. Her heart beat so fast and hard she felt as if it would explode. She stumbled over towards Dewdrop's remains, hoping to Celestia there was still life within him. A touch of his ice-cold foreleg confirmed her worst fears.
"No... Spritz, I-I'm so s-s-sorry..." she sobbed, leaning against the operating table for support.
She was far too late to save him.
A few minuted passed as she quietly mourned and cried. Once the worst of her emotions had left her, Rainbow wiped her eyes and looked over to Twilight. She was examining Dewdrop on her own, a mixed look of disgust, sorrow and wonder on her face.
"An actual full craniotomy... I-I'm so sorry this all happened, but to think I'd ever see one, not even Princess Celestia let me see a real live brain when I was studying A and P..."
"...T-Twilight," Rainbow sniffed. "N-Now is not the t-time... o-okay?"
"Sorry..." she lowered her head and walked over to Rainbow. "As horrible as everything has been here, a part of me really wants to know 'why', you know? Why do all of this..." she trailed off as she pulled her close into a warm hug. The embrace only made Rainbow start to cry again.
"What am I gonna tell Spritz?" she wailed. "I didn't save her brother... I could've saved him. I could've saved him weeks ago...!" Twilight glanced around nervously, hoping Rainbow wasn't attracting any unwanted attention. Her ears flicked when she was satisfied they were alone. "A-And now she's here t-too, what if I c-can't s-s-save her?! What if s-she's already d-dead?!"
"Well, we didn't find her on this floor," Twilight replied calmly and steadily. "We just have to keep looking. She might be on the last level of this place." Rainbow's cries quietened as she struggled to reclaim her emotions; Twilight rubbed her back in an effort to help. "We've come this far, we can't stop now. I'm positive we can still save her. Then we'll go get help, and we'll save everypony here, and we'll make sure everypony who works here pays for what they've done. Right?"
A few gasps for breath, and Rainbow had managed to get a hold of herself. "You're right," she sighed. "We can still save her."
I can still save her.
I have to save her.
I must save her.
"Attagirl!" Twilight cheered. "C'mon, it should just be a little longer to the last staircase. We should get going in case those ponies forgot a... sample." She regretfully glanced over to Dewdrop. Rainbow tried her best to sprint out of the room in determination, but could only manage a half-spirited jog.
Images of dead ponies assaulted her mind as they made their way to the final staircase door. She had seen way more than she had ever expected, way more than she had bargained for. As they finally approached, and Twilight swung the door open, Rainbow's legs shook violently, almost giving out on her entirely. It took all of her willpower to take the first step down.
Down into Tartarus.
Down into hell.