In a tenement on Kwiatowa Street, Karolina discovers a hidden laboratory beneath the hall floorboards. Below the glass steps, an alchemist waits in the fumes of something far older than curiosity.
Karolina stepped into the tenement on Kwiatowa Street and paused at once. The building had a stale, watchful silence to it, as if it had been holding its breath since long before she moved in. She had the flat to herself now, and that freedom still felt unreal, but it wasn’t freedom that made her skin prickle. It was the feeling that something in the house had noticed her.
After the storm, the hallway smelled of wet stone and old wood. Thunder rolled somewhere beyond the windows, fading into a low, uneasy hum. Then she heard it again: a soft knock beneath the floorboards, faint but deliberate, like someone tapping from the other side of a wall no one else knew existed.
Karolina knelt by the stairs and pressed her fingers to the worn oak planks. One board shifted. Then another. A narrow seam opened where there should have been none at all, revealing a descent sunk into darkness. Cold air rose from below, carrying the scent of lavender, ash, and something metallic that she could not name.
She hesitated only once. Then she pulled the boards wider and climbed down.
The staircase beneath the building was made of glass. Not clear, ordinary glass, but something alive with a pale inner shimmer, each step holding her weight with a faint, ringing hum. Vapor curled around her ankles and thickened as she went lower, as though the air itself had been brewed.
At the bottom, Karolina stopped in the doorway of a vast underground laboratory. Shelves lined the walls from floor to ceiling, crowded with leather-bound books, stoppered vials, and round glass bulbs where coloured liquids turned and flashed like trapped lightning. Copper pipes ran into a furnace in the far corner, where a blue flame burned without wood or coal. The room glowed, dim and restless, in shades of green, amber, and violet.
A man sat beside the furnace in a long grey coat. His silver hair fell almost to his waist. In the firelight, his eyes shone with a steady gold that did not look human.
He turned a small vial between his fingers and looked up as if he had been expecting her all along.
“You came sooner than I thought,” he said. His voice was quiet, but it seemed to move through the room like a spell. “Were you not afraid to come this far? Or did the staircase choose you?”
Karolina could not answer. The laboratory had gone still around her. Even the bubbling glass vials seemed to hold their breath.
Then something deep in the furnace gave a violent crack, and a burst of violet light shot through the room, swallowing the man’s face in flame-colored shadow.