The mention of the "last visitor" hit Snape like a physical blow. The air in the dry, silent office suddenly felt as cold as the ice encasing the Basilisk outside.
"Riddle," Snape hissed, his fingers clenching into the fabric of his robes. "You're saying the Dark Lord has been back in the castle this entire time? Under Dumbledore's nose? Again?"
Sebastian didn't look up from a stack of yellowed parchments he was leafing through. "Calm down, Severus. If he were here in the flesh, do you really think I'd be letting the first-years wander the corridors with nothing but a 'point me' spell and a prayer? No, it wasn't the man himself. It was a memory—a fragment of his consciousness trapped in a cursed object. A diary, specifically. It found a host, used their life force to open the plumbing, and tried to finish what he started in the forties."
Snape's eyes darted to the desk, seeing the familiar slant of the handwriting. "Fifty years ago... he was just a prefect then. A boy with a silver tongue and a heart made of ice."
"He was more than that," Sebastian murmured, tapping a particular page. "He was a scavenger. Look at these notes. He wasn't just using the Basilisk as a weapon; he was using this room as a laboratory. He spent his nights down here, feet away from a monster, decoding the work of a Founder. He framed Hagrid, won a trophy, and walked away with a brain full of secrets that even Dumbledore doesn't fully grasp."
Sebastian gave the parchment a final look before waving his wand. The papers didn't just move; they folded themselves into neat, organized dossiers and floated into his expanded bag. "But Riddle is a footnote today. I didn't bring you down here to discuss a failed student. I brought you here for the source material."
Snape, still shaken by the proximity to his former master's ghost, turned his attention to a shelf of journals bound in dragon-hide that looked ancient enough to crumble at a touch. He pulled one out—its surface felt oily, as if the magic inside was trying to seep through the leather.
He opened the first page and began to read, his eyes widening with every line.
[Today, Godric was blathering on again. He wants a wizard who can fight like a dragon—scales that can shrug off a hex and skin that can't be cut by a goblin's blade. A fool's dream, perhaps, but it got me thinking... why should we be limited by this fragile, pink skin?]
"He was trying to improve the Animagus transformation," Snape whispered, his voice thick with disbelief. "That's... that's impossible. The law of magical biology states that a wizard's soul can only resonate with a mundane animal. To try and become a magical creature is to invite the soul to shatter."
Sebastian leaned over his shoulder. "Read the next entry. Slytherin didn't believe in 'impossible.' He believed in 'not yet discovered.'"
[I watched an Animagus shift into a cat today. Utterly pathetic. They spend years of meditation just to catch mice and shed on the furniture. They are afraid. Afraid that if they touch the blood of a phoenix or a manticore, they will lose their humanity. But magic IS the sacrifice of humanity. To go further, one must be willing to become the monster. Starting today, I will refine the potion. I will not be a tabby cat. I am Slytherin. I will be the storm.]
The room was silent as Snape flipped through the pages. The journal was a descent into madness and genius. It wasn't just a recipe; it was a diary of a man tearing himself apart in the name of progress.
"He found the two walls," Snape noted, pointing to a diagram of a wizard's heart. "The magic consumption is the first. Most wizards would burn out like a cheap candle trying to maintain a dragon's form. But the second... the blood."
[Magical blood is alive. It has a will. When you add the blood of a Basilisk or a Chimera to the Animagus draught, you aren't just changing your shape; you are inviting a second soul into your body. If your will is not a diamond, the beast will eat you from the inside out. I have tried to filter the 'personality' from the blood, but every time I do, the transformation loses its power. I am stuck between becoming a mindless beast or a weak man.]
Snape turned to the second journal, his breath hitching. The entries here were shorter, more frantic. They recorded the physical toll of the experiments.
[Failed again. The Dragon's blood was too hot. My skin felt like it was on fire for three days. My eyes have turned a permanent shade of amber. Minerva would call it a tragedy; I call it progress.]
[Third attempt: The Bigfoot. An ape-like creature, close enough to human form to bridge the gap. It worked... partially. My strength has tripled, but I can no longer look in a mirror. My jaw has shifted, my brow has thickened. I look like a brute. A monkey in a wizard's robe. The bloodline conflict is a poison. My own human blood is fighting the magic. It is a war I cannot win.]
Snape closed the book, his hand trembling. He looked at the giant statue of Slytherin in the outer chamber—the ape-like face, the sagging features. "He did it to himself," Snape whispered. "The statue isn't a stylistic choice. It's a self-portrait of his failure. He spent ten years trying to become a god and ended up looking like a beast."
Sebastian nodded, his expression uncharacteristically grave. "He left the school because he couldn't face his peers anymore. He was tired, Severus. Tired of fighting his own veins. He left the Basilisk here not to 'purge' the school—that was just the cover story he gave the more radical students. He left it as a guardian. He loved that snake. It was the only thing that didn't judge him for what he'd become."
The weight of a thousand years of regret seemed to press down on the small office. Snape looked at the shelves of books, then at the empty desk. "There is no inheritance, Sebastian. No secret spell to make you all-powerful. Just the records of a man who broke himself against a wall that cannot be climbed. I'm sorry. You came all this way for nothing but a pile of old journals and some snake spit."
Sebastian didn't look disappointed. In fact, his eyes were glowing with a predatory intellectual hunger.
"Nothing?" Sebastian laughed softly. "Severus, you're looking at this like a potion-maker. You see a failed recipe. I'm looking at this like a pioneer. I see the blueprint."
"The blueprint for what? For turning yourself into a monkey?" Snape snapped.
"Slytherin failed because he was working with the tools of the eleventh century," Sebastian said, his voice rising with excitement. "He was trying to brute-force the transformation with potions and willpower. He didn't understand the underlying structure of magic—the way the soul interacts with the physical vessel. But I do."
Sebastian picked up the final journal, the one where Slytherin admitted defeat. "He thought the bloodline conflict was inevitable. He thought the human blood would always reject the magical blood. But what if you don't 'add' the blood? What if you rewrite the code?"
Snape stared at him. "You're talking about high-level soul-crafting. It's madness. Not even the Dark Lord dared to go that far."
"Voldemort was a collector of power, not an architect of it," Sebastian dismissed with a wave of his hand. "He wanted to live forever, so he cut himself into pieces. That's a coward's way. I want to expand, not divide."
He began packing the remaining journals into his bag with a frantic, rhythmic efficiency. "We've stayed long enough. McGonagall will be thinking we've been swallowed by the lake. And Snape? Don't look so grim."
Sebastian clapped Snape on the shoulder as they walked out of the office and back into the main chamber, where the frozen Basilisk still lay in its icy tomb.
"You'll get your venom," Sebastian promised. "And more than that, you'll get to watch. Within a year, I'm going to solve the problem Slytherin couldn't. I'm going to find the bridge between the wizard and the beast."