Princess Celestia of Equestria went down the spiral staircase that led to the deepest part of the dungeons below Canterlot. Those jail cells were reserved for only the most dangerous criminals from all over Equestria. From serial killers to gang leaders, everyone down here had a murky past, and held almost no compassion or empathy.
Her heart broke when she thought about the pony she was going to visit, held equal to others far more cruel and bloodthirsty than her.
Flanked by two of her finest guards, she advanced through the dark corridors. Her ears picked up on the sound of various growls and insults being thrown at her, but she was too worried with her ever-growing pain and sadness to even try to quiet them. The guards, however, did mind, and with a few glares and commands most decided to shut up.
The three ponies stopped before a cell seemingly like the others. One of the guards stepped up and levitated a key to the lock, opening the door. He gave a nod to the Princess, who, with great fear, stepped inside.
From the opposite wall of the chamber, a mare-like figure was curled up against the wall. She was chained from her legs while a magic inhibitor encapsulated her horn. But the real motive for worry was her noticeable trembling and faint but frantic mumbling.
Celestia stepped a bit closer, careful to not disturb her. She took a deep breath, preparing for what was next, and then spoke. "Twilight?"
The unicorn in question's head shot up, and she turned with a smile. "Princess!" She ran to her, stopping abruptly when the chains tugged at her. She, however, gave no sings of noticing as she looked up to her beloved teacher. "I'm so happy you're here!" Her happiness resembled that of a filly getting a new toy. "Can we leave now? We have a lot to discuss about my new discoveries!"
The alicorn carefully chose her words. "That...is not possible at the moment, my faithful student. We can just discuss your research down here." She knew the purple mare would not go against her wishes.
Twilight's smile just grew brighter. "Sure, Princess." She sat down, getting as comfortable as she could in that cold stone floor."Where do I start?" She gazed at her questiongly.
"How about from the beggining? When the idea came to you?"
The unicorn nodded. "I was reading the theories of Dr HeartStrings. He said that magic is generated in the brain, and, while it is connected to the soul, it does not come from there." She rocked back and forth slightly as she spoke. "However, since disecction is only allowed on already deceased bodies, the traces of magic dissappear and there is no way to prove that statement."
Twilight did not notice the utter sadness and despair in her teacher's eyes, and instead continued. "If, however, a live body was tested, then the theory would be proven either wrong or right. If it was true, then it would have been absolutely revolutionary for science and and anatomy. So I had to try. For the good of science."
Silence fell as the purple mare finished, awaiting for her companion's reaction. Celestia tried to sound interested, and asked another question. "What did you do, then?"
"I needed test subjects, so I took them." Her smile grew even bigger, if that was posible, her happiness changing from child-like to mad-like. "And what better ones than my best friends? Not only am I throughtly aware of their sleeping and eating habits and their enviroments, but they said they would help me with anything! So I took their offer and tied them up in the basement. You know, so they wouldn't get hurt or something."
The Sun Princess had passed from slightly disturbed to fully horrified. The whole trip here she had been hoping that it was some mistake, that it couln't possibly have been her prized student.
And now, reality was crushing her.
"I started with Rainbow and Fluttershy." Twilight continued, as calm as one would have been when talking about puppies. "I cut the first layers of the skin, fom the brain to one of the wings. Unfortunately, both died from a a combination of the shock and the pain before I could make much progress." She did not show regret as she acknowledged killing her best friends. "I continued with Applejack and Pinkie Pie. The latter started screaming, and I got so frustrated that I accidentally cut an artery, and she bled to death. With Applejack I tried cutting just one part of the head and then following to the muscle, but it still didn't work." Her voice had a tint of frustation, not the regret one would have expected from someone sane. Then again, no one sane would have even thought of doing what she did. "Rarity was my last hope. So I decided to use to spell to minimize her pain, something I hadn't done before in fear of altering the results." The frustation vanished from her tone, and her eyes had the satisfaction of accomplishing something you had worked hard for. "From her, I was able to conclude that magic, contrary to Dr HeartStrings's theory, does not originate in the brain." She clapped her hooves together. "So, what do you think?"
Only once before had Celestia felt so heartbroken, when her sister rebelled against her.
But now, apart from the gult and pain, she felt disgusted and shameful that the filly she had raised and loved like a mother, had turned on her friends for a experiment.
"Twilight," She began, her voice almost cracking. "Do you not realize what you have done?"
"That was what I told you in the letter." She sounded confused, clearly not understanding the weight of the situation. "I managed to disprove Dr HeartStrings's-"
"Not that!" The alicorn was desperate to make her student open her eyes. "You killed your friends, Twilight! The Elements of Harmony! Your best friends!" She felt her eyes start to water, and tried her best to keep the tears in.
"And? It was for the good of Equestria." She shrugged. "I'm sure they would have liked to know that."
Celestia wanted to reply, but found no words to do so.
I'm sorry, my student. I'm sorry I planted the idea of research being the most important thing so deep that it has led you to do this. She thought as she ignored Twilight's attempts to gain her attention. She turned and headed for the door.
Once she was almost out, however, she slightly turned her head and spoke her final words to her.
"Your trial is to be held within three days."