The heavy oak tables of the Kaer Morhen library, once used for sharpening silver swords and cleaning monster trophies, were now buried under a different kind of clutter. At seven years old, Isaac Newton was small enough that he had to sit on a stack of ancient bestiaries just to reach his workspace, yet his presence filled the room with a quiet, intense gravity.
While the other boys were out in the courtyard, their shouts echoing as they practiced footwork, Isaac sat in the silence of the dust motes. His fingers, stained with charcoal and ink, flew across parchment with a precision that was unnerving for a child.
Vesemir entered the room, his heavy boots thudding against the stone. He stopped behind the boy, peering over his shoulder at the scrolls. He saw diagrams of falling bodies, strange curves he called "fluxions," and meticulously drawn anatomical sketches of ghouls—not as monsters to be feared, but as biological systems of muscle and bone.
"Isaac," Vesemir rumbled, pointing to a page covered in complex symbols and Greek letters. "I've seen the scripts of the Aen Seidhe and the cryptic ciphers of the Nilfgaardians. But I have never seen... this. What is it?"
Isaac didn't look up, his quill scratching rhythmically. "It is Physics, Uncle Vesemir. The study of matter and its motion through space and time. This specific page is a calculation of the force required for a Griffin to achieve lift, given its mass and wing surface area. It shouldn't be able to fly, aerodynamically speaking. It must be using a localized gravitational distortion."
Vesemir blinked, his golden eyes clouded with confusion. "Physics? Gravity?" The words felt like lead on his tongue. To a Witcher, a Griffin flew because it was a monster. It was simply the way of things. "And these?" he asked, pointing to another stack.
"Biology and Chemistry," Isaac replied simply. "The laws of life and the laws of elements."
The centerpiece of Isaac's desk was a massive, unfolding parchment. In his previous life, he had died before the modern periodic table was codified, but here, with a mind unburdened by his previous failures and aided by the tangible presence of magic, he was rebuilding the map of the universe.
He had listed the familiar—Lead, Iron, Silver, Mercury—but the table was expanding. He had categorized Magnesium, Phosphorus, and Sulfur, and was currently attempting to isolate the properties of Dimeritium and Meteorite to see where they fit into the atomic weight scale.
"You spend your days naming the very dirt we walk on," Vesemir said, shaking his head. He picked up a page covered in what looked like a logical proof for the existence of a vacuum. "The other boys call you a 'book-wyrm.' They think you're afraid of the sword."
Isaac finally paused, setting his quill down. He looked at the old Witcher with a gaze that was ancient and piercing. "I am not afraid of the sword, Uncle. But a sword is only a lever. Its effectiveness is governed by mass, acceleration, and the angle of incidence. If I understand the Mathematics of the strike, I do not need to be the strongest. I only need to be the most precise."
Vesemir watched the boy return to his work. Isaac didn't just read the alchemical books of the School of the Wolf; he corrected them. He crossed out vague instructions like "stir until the color of a sunset" and replaced them with exact temperatures and molecular ratios.
To Vesemir, the boy was an enigma. He was only seven, yet he spoke with the authority of a Grandmaster. He didn't see a world of "magic" and "monsters"; he saw a world of Laws that had simply not been written down yet.
As the sun set over the Blue Mountains, Isaac lit a single candle, the light reflecting off his silver hair. He wasn't just a child in a basket anymore. He was a pioneer, mapping a world that didn't even know it was lost.
Vesemir turned to leave, a strange sense of hope mingling with his confusion. "Carry on then, Scholar. Just don't forget to eat. Even 'Biology' requires fuel."
Isaac smiled faintly, already lost in a calculation of the refractive index of a foglet's breath. The darkness of the Continent was vast, but he was building a lantern out of pure logic.
******
The heavy portcullis of Kaer Morhen groaned upward, complaining against the frozen mechanism as three riders crested the final ridge. Geralt, Eskel, and Lambert—the last survivors of a dying breed—dismounted in the courtyard, their armor caked in the grime of a long season on the Path.
They expected the usual silence of the graveyard-keep. Instead, they were met by the high-pitched shouts of children.
A group of boys, barely ten years of age, were practicing footwork drills under the watchful, weary eye of Vesemir. They moved with wooden swords, their faces flushed with effort but their eyes still bright with a human spark—a spark usually extinguished by the terror of the looming Trials.
"Vesemir," Geralt greeted, his voice a low rasp as he unbuckled his sword harness. "The courtyard is crowded. Another Law of Surprise?"
Vesemir nodded solemnly. "Surprises, strays, and those with nowhere else to go. But things are different now, Geralt."
Lambert snorted, kicking a clump of frozen mud from his boot. "Different how? Are we opening an orphanage, or are we sharpening the knives for the Grasses? I'm not in the mood to listen to more screaming this winter."
Vesemir's expression hardened. "There will be no screaming. Not yet. I've seen enough boys die on those stone slabs. Until we can find a way to negate the death rate—to stop the Grasses from tearing the heart out of the living—none of them go under the knife. For now, they learn the blade, the bombs, and the oils. They learn to be survivors, not mutants."
Lambert looked around the courtyard, counting the heads. His eyes narrowed. "You're missing one. The silver-haired whelp you found in the basket seven years ago. Isaac, wasn't it? Don't tell me he couldn't handle the mountain air."
"Isaac is exactly where he always is," Vesemir replied, gesturing toward the flickering light in the high window of the library tower. "Buried under a mountain of parchment and glass. He hasn't left that room since the first frost."
"Still playing at being a clerk?" Lambert smirked, leaning against a stone pillar. "What's he doing up there? Writing poems to the moon?"
"Hardly," Vesemir said, his voice tinged with a mix of pride and bewilderment. "He calls it 'Research.' He's obsessed with the chemical composition of the mutagens. He claims our ancestors were 'clumsy' with their measurements. He's trying to rewrite the formulas of the founders to reduce the pain of the transformation."
Eskel looked up at the tower, his scarred face thoughtful. "A seven-year-old trying to fix the Trial of the Grasses? That's either brilliant or insane."
"With Isaac, it's usually both," Vesemir muttered. "He doesn't think like a Witcher. He doesn't even think like a mage. He treats the world as a giant machine that just needs the right oil to run smoothly. He's mapped out the very elements of the earth—things I can't even pronounce."
Geralt looked at the light in the tower. He remembered his own Trial—the agony, the darkness, the feeling of his blood turning to liquid fire. The idea that a child could look at that horror and see a mathematical problem to be solved was unsettling.
"He's a strange one, Geralt," Vesemir added quietly. "He doesn't want to be a hero. He wants to be an architect of a new era. He told me yesterday that 'knowledge is the only light that doesn't cast a shadow.'"
Lambert rolled his eyes, though his cynical edge seemed slightly blunted. "Great. A philosopher-witcher. Just what the world needs—someone to explain the physics of why a Katakan is eating your face."
Geralt didn't smile. He just watched the window. "If he can make it so those boys out there don't have to die... he can call it whatever he wants."