At seven seventeen, the air in the corridor trembled all the way. A metallic, deep tone cut through the morning conversations and the rustling of rucksacks like a blade. People froze, someone dropped a cup of tea. The bell - the big, real one, from the old tower above the auditorium - rang out, although for years we had only had electronic beeps, brief and soulless. And yet, as Mr Staszek, the caretaker, kept repeating, "that one is already a decoration". "Did you hear that?" Maks peeked out from behind his hoodie, and his backpack with game patches slammed against my shoulder. "I'm not deaf." I brushed my hair out from under the cap. It smelled of wet jackets, rubber from the soles and something that resembled old paper. "Impossible." Igor, who always double-checks everything, looked at his phone. "It's 7:17 a.m. But the bell? After all, they disconnected it during the renovation." Outside the biology room, Mrs Sobanska, the headmistress, was talking to Mr Staszek. I caught excerpts: "emergency", "no one has keys", "forbidden to enter the old wing". The word "ban" sounded like an invitation. The bell fell silent, but the echo still clung to the ceiling for a while. Then everything returned to the usual: the school beeping from the speakers, laughter, someone shouting that there were bargains in the shop again. Only I felt that the sound stayed somewhere under my skin. In the first lesson, Mrs Zawadzka had us write an essay about 'the weirdest morning at school'. She was familiar with irony. The pens scraped away and I couldn't stop thinking about the stairs leading up to the tower. I'd heard so many stories about them that they could be covered in textbooks: how students used to hide firecrackers up there, how someone found a box of letters from before the war, how the clock mechanism had its own humour. But since the installation was replaced, the old part was padlocked and decorated with red and white tape. Halfway through the lesson, as Mrs Zawadzka was leaning over cursive sentences from the last bench, my notifications vibrated simultaneously with Maks and Igor's phones. We looked at each other. An e-journal message appeared on the screen: "Event added: Bell rehearsal. Time: 7:17." There would have been nothing strange about this, were it not for the fact that the sender's name was "Doe", with three initials underneath: L.M.I. I raised my hand. "Can I go to the toilet?" "One each." Mrs Zawadzka fixed her gaze on me, but nodded. Before I left, I pointed to Maks and Igor under the bench. They caught up with me under the cup display case. "Who does bell rehearsals at seven seventeen?" hissed Maks. "And why does the message have our letters?" "Maybe someone is playing a joke on us." Igor said more quietly than usual. From stress, the shy red spot on his neck darkened. "Or it's a ... hmm... a system error." "A bug that knows our initials?" I raised an eyebrow. "We're going upstairs on a long break." "After all, that part is closed." "Closed as in locked." I moved my eyes over the photograph in the display case - the class of 1997. Front row, third from the left was a boy in a denim jacket smiling. On his chest was pinned a pin badge: three concentric circles. Two days ago I had seen the same symbol scratched on a bench under the window in our classroom. Now it appeared next to it in the notice - circles instead of ornaments. Coincidence? At the long break, the corridor was boiling. An orchestra of thunder - lockers clattering, trainers creaking, chairs clashing. Teachers with mugs of coffee flitted between the crowd. We passed Mrs Celina from the library: she bowed to us with that chin movement of hers, as if confirming every now and then that books exist. The old wing started behind a heavy door next to the auditorium. Someone had attached a note: "Renovation - entry prohibited". The card was fresh, and the tape that was supposed to 'forbid' hung sagely, like a mere scarf. "If we get caught, there will be a baptism." Maks licked his lips. "If we go back in and someone else gets in first, I'll be scolding myself for the rest of eighth grade." I pushed open the door. It creaked open. Behind them, twilight spilled out, a few degrees cooler. The smell of dust hit us in the face like a thick book. The corridor was narrower and lower than the 'new' ones. The walls were peeling like paint on an old fence. To the left hung a cork board with overdue notices: "Missing hoodie - prize", "Chess circle", "Looking for a choir for the school's anniversary celebration". Underneath, someone wrote in pencil: 7:17, 7:17, 7:17... The numbers repeated like drums. "Someone did this yesterday?" Igor moved his finger over the digit. The graphite left a smudge on his pad. "Nobody comes in here.... supposedly." Maks looked up. Above us ran the wooden galleries leading up to the tower. When I was younger, I'd imagined this place living its own life after school, like my grandfather's attic. The stairs creaked. It got quieter with each step, as if the school had left behind us like a silent sea. Only our breaths and the clatter of heels. On the mezzanine hung an old, cracked clock with no hands. Someone had stuck a yellow note on it: "Time doesn't count if it doesn't beat". I trembled, not from the cold. "Why is it so windy out here?" Maks adjusted his hood. Indeed, a draught was blowing in from above, carrying with it the smell of grease and something sweet, like toffee. "Maybe the window is ajar." Igor took the torch out of his phone. The screen flicked on and.... went out. Mine too. Maks cursed under his breath. "Really?" I muttered. "It's like a Faraday can upstairs?" "The network doesn't work. But the torch should ... never mind." Igor put the phone away and took a tiny battery-operated light from his pocket - such a man. Yellow light spilled down the stairs. A sound went ahead - quiet, similar to a ticking, although there were no clues. On the next floor, the corridor turned at a window with a milky glass pane. Someone had drawn circles with their finger. Three, one inside the other. Under them: "Come in." "Who 'you'?" Maks asked, but I didn't answer. I felt that soft thing in my stomach that comes just before a test when you can't remember the formula and you need to count. The door to the top was even heavier than the one downstairs. They had green paint, stripped down to the wood in places. The lock looked straight, but someone had replaced the handle with a new one. I tried it. It gave way immediately, as if the place wanted to let us in. The tower room was smaller than I had imagined. There was a bell mechanism in the middle - a cogwheel and axle, connected to what looked like a long-disconnected drive. A bell hung from the ceiling, its rim worn from years of striking. In the aisle stood a table, and on it a checkered notebook, cracked along the spine. Next to it a thermos and a mug with a lip print, still damp. I coughed as dust danced in my nose. "Someone was here a while ago." Maks raised an eyebrow. Igor walked over to the table and put his fingers on the notebook, as if he was afraid the paper would bite him. He opened it. On the page were several sentences written in even, slanted handwriting: "Calling is only allowed at 7:17 a.m. Otherwise you get angry." Underneath, three short dashes and the initials: L.M.I. My heart did a flip, then a second one. "This is not funny." "Maybe... it's letters from something else." Igor said, but he sounded like someone explaining something to himself. On the wall, just above the windowsill, someone had written in chalk: "You've come. Finally." The chalk was still crumbling at the edges of the letters, as if they had just dried. "I don't like it." Maks reached into the thermos, touched it from the top and withdrew his hand. "Warm." For seconds we stood as if pressed into a pause. Then the air in the room trembled, and the thin metal chain that ran from the mechanism to the bell vibrated of its own accord. Once. A second. A third. At the same moment, our phones - dead a moment ago - vibrated simultaneously. On a black screen, without any icons, a white sentence popped up: "One more step." Somewhere under the floor, something clattered. When I turned my head, I saw that the door behind us was no longer so wide open. They closed as if someone had laid a hand on them. And then, above our heads, a bell played a single tone - quieter than before, but so clear that it made my stomach twist. "Hello?" called back someone from a dark corner that we hadn't illuminated with a lamp before. The voice was soft, deep, as if it had known us for a long time. "Lena. Maks. Igor. You're late..."