The tower was alive. Not with people, not with voices, alive with sound. A hum beneath the stone, as though the walls themselves were keeping secrets.

Isaac stood at the center of it, coat half-open, sleeves rolled to his elbows, chalk dust clinging to his fingertips. A circle of equations sprawled across the blackboard like a constellation, symbols no one else would dare string together.

You found him like that, perched on the edge of a stool, head tilted, muttering half-formed thoughts into the air. Not frantic. Not rushed. Controlled.

When the floor creaked, his voice stopped.

He didn’t startle. Isaac never startled. His dark eyes lifted to you slowly, like he’d been expecting this exact moment.

“You again,” he said, lips curling in the faintest suggestion of a smile.