After lessons, Kacper and Lena hear something moving under the door of the abandoned biology room at Gymnasium 7, and their curiosity leads them straight into the dark.
The school after dark felt like a place built from memory rather than brick. Gymnasium 7 had emptied out hours ago, but the corridors still seemed awake, stretching away in pale bands of light and shadow, every sound softened and sharpened at the same time.
Kacper and Lena were meant to be finishing a chemistry project, yet the project was done and forgotten, abandoned somewhere between the last bell and the moment boredom turned into mischief. They drifted from one empty corridor to the next, speaking in low voices, as if the building might resent being disturbed.
"What if we check the old biology room?" Lena asked.
Kacper stopped walking. Even now, people still talked about that room in half-finished sentences. No one used it anymore. The accident from years ago had been explained, repeated, and then carefully avoided, but the room itself had never quite stopped feeling wrong.
They crossed the corridor together, stepping around the broken patches of fluorescent light that flickered overhead. At the far end, the door to the biology room stood shut, its paint dulled by time. The lock looked rusted through, useless almost to the point of being decorative.
Then they saw the light.
It was faint and greenish, seeping out from the narrow gap beneath the door.
Kacper felt his throat tighten. Before he could say anything, something moved inside with a dry, scraping sound, slow enough to be deliberate. Lena caught his sleeve, and he realised she had gone completely still.
"Did you hear that?" she whispered.
The sound came again, closer this time, as if whatever was inside had reached the door and was testing it from the other side. Kacper pulled a torch from his pocket, though he had no idea whether he wanted to see more or less. He put his hand on the knob.
It turned.
The door gave way without resistance, opening a few centimetres into darkness. The green light sharpened along the edge of the frame. Lena drew in a quick breath. Kacper leaned forward just enough to see movement inside, and then a shape shifted out of the dark, rising slowly toward the crack in the door.