Two regular updates in a row? What is this I don't even.
Princess Celestia brushed past the stunned Twilight, her mane and tail glittering in the light from the eye sockets of the skulls like multicolored clouds. She spread her powerful-looking white wings, and looked back over one to shoot her student a beatific smile.
"I brought him here especially for you, Twilight," she said, nodding to Big Mac, whose naked green eyes rolled wearily towards her. "As you can see, I just couldn't help myself. I wanted to hear him scream...but he's ever the strong, silent type. Maybe you'll have more luck."
Twilight's brain barely even registered what Celestia was saying. Her eyes, wide with horror, were fixed on the stallion in front of her. Before she even realized what she was doing, her hooves shuffled forward, and then she trotted, and then she was galloping over the smooth stone of the torture chamber, ducking underneath the the princess's outstretched wing in order to get to Big Mac. Spiny feathers raked through her mane and scratched at her back.
"Oh...oh, my goddess..." Twilight moaned, coming to a stop right in front of the rack that Big Mac was lashed to. She felt tears well in her eyes.
"Now, now, Twilight, you really don't need to get so worked up," Celestia murmured, her golden horseshoes clinking against the stone floor as she stepped forward. She folded a horrifyingly-spiky wing around the smaller mare, and Twilight shuddered violently. "Mr. McIntosh Apple is just a teaching tool. Something I can use to assess your skills, and pass some of my simpler techniques on to you."
"How can you say that?!" Twilight cried, twisting away. Celestia's sharp feathers tore red scratches in her coat that immediately began to well with blood, but she didn't notice the pain. "He's Applejack's brother-Princess, he's a pony, just like we are, an equine being!" Her muzzle trembling, she reached out to gently touch Big McIntosh's chest with the edge of her hoof, just to try and comfort him a little. He flinched, and Twilight withdrew, shooting a furious glance at her princess. "How the hay could you do this to him? To them?"
She swept a foreleg in an arc, encompassing all of the broken, violated ponies in the room. She was shaking with rage, fear, and disgust, her mind doing loop-the-loops out of utter shock. Somewhere, in the back of her mind, she realized that she had sworn, and she was embarrassed about that. Somepony who knew Equish as well as she did shouldn't have to resort to profanity to get her point across.
Celestia sighed, rolling her one visible eye in exasperation and taking a step forward. Twilight scrambled back. Her real hoof made a rasping noise as the keratin slid across the stone, but the one made of the solar princess's magic was almost totally silent.
"Twilight," Celestia began in a firm tone, "do you honestly think that these ponies..." She glanced around her. "...are the same as me?"
"What are you talking about?" Twilight whimpered. She didn't want to be here, in this stinking room surrounded by dead and dying ponies who had had truly unspeakable things done to them. She wanted to go back up to the palace, where the strange red tint would vanish from Celestia's magic and there would be nothing vicious in the eye that her mane didn't cover when she smiled at her.
But, somehow, Twilight knew that that would never happen. The princess that she had loved for so many years was gone, replaced by this...monster.
"Because they are just ponies," Celestia explained. "And I..." She stepped back, raised her head, and spread her wings as wide as they would go. The bloody glow from the eye sockets of the skulls that lined the walls dimmed, and soon the only light came from Celestia's horn. There wasn't even the slightest hint of gold in her magic now. The red glow pulsed and throbbed like a diseased heartbeat, and in its terrible light, Celestia's visible eye was a soulless black crater to Twilight. For just a moment, she saw worms and maggots writhing between her razor-sharp feathers, rot creeping up her legs, and ragged strings of decaying flesh drifting in the foul clouds of her mane and tail. "...am a god."
The light returned to normal. Twilight trembled against the floor, realizing that she had dropped to her belly out of pure fear.
"But I didn't bring you down here to tell you why I need to teach you. At least, not yet." Several dozen pinpoints of red magic appeared all over Twilight's body, and hauled her to her hooves before gently pulling her forward. Her hooves scraped against the floor until she was standing directly in front of Big McIntosh, her lavender eyes locked with his apple-green ones. "Show me what you can do, Twilight."
Instruments-scalpels, hooks, saws, thin wire-floated off of the walls, drifting over to bob in a circle around Twilight. Everything she could possible need to make a pony scream and bleed and die was at her hooftips. But she didn't magically reach or any of the tools. She kept her eyes on Big Mac's. Eyeballs themselves were actually pretty expressionless, Twilight realized. It was all the flesh and muscle around them that conveyed what a pony was feeling. She couldn't tell at all what was going through Big Mac's mind. Actually, without eyelids, he just looked comically surprised. She felt a hysterical giggle threatening to break its way out of her muzzle, and crushed it as best she could.
Twilight ignited her horn, and Celestia smiled eagerly. A magenta glow flickered over a scalpel, a bonesaw, and a crescent-shaped knife, then vanished. It reappeared on the bindings that held Big Mac's left forehoof to the rack. As the magenta light pulsed and fluttered, the leather straps began to undo themselves.
Immediately, the instruments of torture clattered to the ground, horrifyingly loud. Twilight winced, and the glow of her magic vanished.
"No," Celestia said forcefully. The light dimmed again, and Twilight's magical leg went completely red. She glanced over her wither to look at it, and her mouth dropped open in horror.
The magic no longer had all the clean lines and curves of a mare's leg. It was bubbling, heaving, like something inside was trying to claw its way out. Twilight saw the vague shape of a head emerge, with empty eyes and a gaping mouth, and she couldn't help herself. She screamed, and instinct commanded her to gallop away from the monster that was trying to tear itself free from her leg. But she couldn't escape from it-it was attached to her.
Bolting across the room and dragging her grotesque, useless leg behind her, Twilight crashed into a stone table, knocking herself down. She landed on her back, her forelegs snapping tight over her chest in an instinctive effort to protect her vulnerable underside. Her writhing hindleg stuck straight up in the air, taking up her entire field of vision. A pair of ragged forehooves, formed of the same red magic as the leg itself, protruded from the side. She screamed in horror, her throat aching and the sound thin and ineffective, as the hooves twitched and the legs that they were attached to began to drag themselves from the seething primordial mass of her limb.
Oh, goddess, oh, goddess, Twilight babbled inside her head. She heard a moan that must have come from Big McIntosh-was Celestia hurting him again? Was he trying to ask her what was wrong?-and answered it with one of her own. She couldn't cope with whatever fresh horror was being born from her body and her princess's magic.
But, just as the horrible empty-eyed head reappeared, the half-formed monstrosity dissolved and the magic of her leg calmed down. Twilight's chest heaved with deep, panicked breaths as it returned to its previous, wonderfully-familiar form. The light brightened again, and a cloud of Celestia's magic rolled her over and carried her back to where Big Mac hung, faceless and defeated.
"Really, Twilight, you should know better by now than to try and shirk your duties." The monarch regarded her trembling student disapprovingly before setting her down. "But if you're truly that intimidated, I'll start."
Celestia picked up a scalpel from where it had fallen on the stones, twirling it surreptitiously in her bloody magic as she did so. She placed the point where the two halves of Big Mac's clavicle met, and he shook. "Big" McIntosh Apple, who spent his days bucking apple trees so hard that the sound of his hooves meeting the wood echoed over Ponyville like a gunshot, who towered over every other stallion Twilight had ever seen, who had once galloped fearlessly into the heart of a mob of squabbling fillies to try and stop a runaway spell...shook with fear. Twilight bit her lip to keep from whimpering in sympathy.
With a flick of her magic, Celestia sunk the point of the blade as deep into Big Mac as it would go. He winced as metal met bone. Then she drew the scalpel downwards, smooth as silk, over the ridge of his sternum and the bulge of his abdomen, until she reached the resistance of the pelvic bone. The incision began to weep blood almost immediately. The opposite edges lit up with magic, and Celestia ripped the cut wide open with a horrific wet tearing sound-as if she were opening curtains.
Twilight gaped at Big Mac's exposed ribcage, glistening with blood and other bodily fluids. Intercostal muscles twitched, blood drizzled from one bone to another, and loops of yellow-gray intestines pressed heavily against a thin, transparent sheath of connective tissue.
"Apple farming must do wonders for one's internal organs," Celestia murmured, eyes roving appreciatively over Big Mac's guts. "Wouldn't you agree, Twilight?"
Twilight's muzzle didn't want to work. She couldn't speak.
Big Mac's ribcage glowed briefly red before cracking apart into two halves with a noise that made Twilight's empty stomach heave. His eyes rolled back in his bare skull as his heart fluttered in its sac and his lungs billowed. Pericardium, Twilight remembered numbly. That's what that translucent sac around his heart was called.
"You've perused the most recent version of Hay's Anatomy, haven't you, Twilight?" Celestia asked. "Tell me, what is this?"
She pointed the scalpel at a deflated-looking, J-shaped organ tucked up underneath the slick dome of the diaphragm.
"Stomach," Twilight croaked.
"Correct." With a few quick slashes and a blaze of magic, Celestia severed and cauterized the esophagus and the duodenum. Then she lifted the stomach out, slitting it open and examining the contents.
"Nothing but acid," she noted, shaking her head and showing it to Twilight. "Though I suppose that's to be expected. I haven't given him anything to eat since I tied him up."
She smiled, suddenly, and lifted the flayed organ to Big Mac's bare, bony jaws, casting a glance conspiratorially at Twilight. "How amusing do you think it'd be to make him eat his own stomach? I think it would be so much fun to watch the end of his esophagus burst open and spill everything into his abdominal cavity..."
That shredded the last vestige of Twilight's self-control. She turned and bolted, out of the torture chamber and into the pitch-black tunnels beyond.
So, I know a lot about the internal anatomy of humans, but not all that much about that of horses. If Big Mac's organs seem out of place or are inaccurate, that'd be why. Though, just judging by how FiM ponies look, I'd guess that their organ layout probably resembles that of a human than of an actual horse.
My God, I am a terrible person.