Three friends spend the night in a locked school on Poplar Street, chasing a mystery that begins with a flicker of light and leads them toward the cellar door.
At the end of June, the old school on Poplar Street looked almost unreal. The long corridors were striped with shadow, and the bright drawings pinned along the walls seemed to shiver in the dim light. The holidays had begun, the classrooms were empty, and only three children were still inside: Olga, Antek, and Janek.
"Did you see that? The light flashed again!" Olga whispered. Her thick pigtails trembled as she stared down the corridor.
Antek pressed himself against the wall and glanced at the corkboard beside the door. "It’s probably just a reflection from the streetlamp," he said, trying to sound brave. It did not help much. His heart was knocking so hard he could feel it in his throat.
Janek pushed open the library door, and it let out a long, miserable creak.
"I heard something," he said at once, lowering his voice. "I’m sure there’s someone in there."
That was how the three of them ended up spending the night at school. They had decided they wanted to find out what really happened in an empty building after dark. The teachers never stayed late. The cleaners never went near the basement after sunset. And the older pupils had plenty of stories, each one stranger than the last.
They came prepared, or so they told themselves: torches, a notebook, and a backpack full of sweets for courage. At first, it almost felt like an adventure. They walked slowly through the familiar halls, whispering and grinning at their own nerves. But as the clock in the corridor struck midnight, the school changed.
The air turned cold. The walls seemed to hold their breath. Then, all at once, the light at the end of the corridor went out.
Olga gripped Antek’s arm. Janek stopped near the stairs leading down to the basement.
"Did you hear that?" he whispered.
All three of them turned toward the padlocked cellar door.
It was no longer shut.
The latch hung loose, and the door stood open a crack.
"It was locked," Antek muttered.
Something shifted behind them with a soft scrape. A dark shape slid across the floor and vanished into the shadows. Olga took one careful step forward, and the boys followed, their torch beams shaking in their hands. Then came the sound again, slow and dragging, as if something heavy was being moved over the concrete below.
From deep inside the basement, a whisper rose into the cold air.