After the holidays, the school smelled of fresh floor polish and wet jackets. Lena, in her second year of secondary school, was moving her finger across the new timetable. In the middle of the week, a mysterious object arrived: History of Place, Room 314, Third Block. This block had been closed for years with tape and legends of a flooded archive. A bell cut through the din of the corridor and Lena pulled off her cap as if removing her helmet before entering the game. At the stairs she met Kacper with a skateboard under his arm and Zosia with a steaming thermos. Kacper raised an eyebrow as if recalling their old, unspoken agreement just now. "Did you hear about three hundred and fourteen?" he asked in a half-hearted voice, looking around the still empty corridor. "They say they found heavy cabinets in there full of letters from before the war." Zosia pointed to the red ban that had disappeared from the railing last night. "Since they opened it, I guess it's safe," she added, although it sounded more like a wish than a certainty. The door to 314 creaked softly, as if it had been waiting a long time for this move. New benches stood inside, but the walls remembered gas lamps and long cast-iron radiators. On the desk lay a metal box, a bunch of old keys and white gloves. In chalk on the blackboard someone had written today: Please put the phones in the box. Lena bent down to pick up a pencil that had rolled under her chair. Instead of it, she found a folded piece of paper - a floor plan with unmarked stairs marked in red pencil. A woman wearing a woollen coat and carrying a file of folders appeared in the doorway. "I'm Mrs Rybak, I look after the school archive," she said, placing the box on the desk. "This is where we learn to read traces, not just dates and names." The phones landed in the box, and the room seemed to let out a quiet breath at once. Mrs Rybak unrolled the list and counted them twice, then furrowed her brow. "There should be nineteen of you," she muttered and fell silent, adding after a moment: "Missing... Julia Nocoń." No one raised their hand, no one associated the name in that class today. Lena unfolded the plan she had found so that no one could see the back. There was a pale pen note in the margin: Julia Nocoń - see stairs behind the board. Her heart picked up its pace, but she feigned calm as she quietly turned another page. "Who knows Julia?" asked Mrs Rybak again, suddenly seemingly quieter. Then something rattled from the side of the blackboard, three short, very distinct thumps. The lamps blinked, a metal key slipped out of its bundle and rolled across the floor. Lena felt a cold draft, as if there was air oozing from under the blackboard. The blackboard moved a hair's breadth, and a knock sounded again behind her - two short, one long.