On a holiday night, Marta and her friends slip into an abandoned school to trace a strange light in the attic and end up face to face with something they were not supposed to find.
By the time evening settled over town, the abandoned school looked less like a building and more like a wound cut into the dark. Marta stood at the broken gate with her rucksack digging into one shoulder, listening to the cicadas and the restless breathing of Igor and Paula beside her.
Igor kept pretending this was funny. Paula did not. She stared up at the top floor, where, every night at almost the same hour, a pale light had started blinking behind the attic window. The school had been closed for ten years. No one should have been up there.
"If we're going in, we'd better do it now," Paula said, her voice barely louder than a whisper.
The three of them crossed the weed-choked courtyard. Dry branches scraped at Marta's legs, and the front door yielded with a long, complaining groan that seemed far too loud in the empty yard. Inside, the air was cold and stale, thick with dust, damp plaster, and the ghost of old books. Their footsteps rang down the corridor and came back to them thinner, stranger, as if someone else were walking just a little behind.
Igor lifted his torch, the beam wobbling across cracked walls and peeling notices. "You know this is where the headmistress vanished, right?" he muttered, trying for a grin and missing it by a mile.
Marta didn't answer. She was watching the staircase.
The light in the attic window had been pulsing for several minutes now, weak and blue, like a heartbeat trapped behind the bricks. With every step upward, the silence grew tighter around them. The door at the top of the stairs stood half open, and a thin strip of that same blue glow slid through the gap.
Paula reached for the handle first.
The door swung inward, and all three of them stopped dead.
In the middle of the attic, between overturned benches and maps gone yellow with age, stood a figure holding something close to its chest. The blue light vanished at once. In the dark that followed, a low hum rose from nowhere at all, soft at first, then steadily louder, until Marta could feel it in her teeth....