The rain had been drawing slanted lines on the windows of High School No. 3 in New Gardens for several hours. The empty corridors reflected the light of the neon signs like a river of glass; the smell of old textbooks mingled with that of floor polish. The pale reflections of the lamps trembled in the cup cases, and from the end of the main corridor came the quiet buzzing of the ventilation machines, equal to the breathing of a sleeping building. Nina put her rucksack on a bench under the evacuation plan board. She didn't like to stay after class, but the film club was due to shoot rehearsal footage on Friday, and she promised to find good interiors. Late November was great for shooting: cold light, wet streets, windows that looked like eyes. At the same time, everything was a reminder that it was almost winter - and that school after dark is a different world. - Did you wait long? - Maks slid out from around the corner, with his hood stuck to his hair. Slung over his shoulder was his camera bag; the straps were imprinted on his jacket in even lines. - Only a moment. 'Leila texted that she'd be right over,' Nina replied, tapping her finger on her phone screen. The chat icon 'Film Circle 3LO' flashed. Leila arrived three minutes later, notebook in hand and a tea cup that smelled of mint and honey. They stopped together by the red and white tape stretched across the east wing. On a piece of paper taped to the door was the print: 'Installation repairs. Please do not enter". Underneath, someone had added in pen: "Seriously?" and drew a sad face. - I wonder what they're actually doing there," Maks muttered. - 'Yesterday after training I saw that the lights were on inside, even though the caretaker said everything was switched off. - 'You know what's weird? - said Nina, staring at the electronic clock board above the secretariat. - 'That bell. Someone said it last rang at nineteen zero seven. Exactly. Why ring at such a time? - Urban legends,' Leila waved her hand, but a note of curiosity sounded in her voice. - 'Let's go to the library. Ms Rose probably has a plan of the building. Maybe we'll find something more interesting than taped-up tape. The school library, hidden away on the first floor, was warm and smelled like a sultana box - old paper and glue. Mrs Rose, petite and always wearing a scarf, raised her eyes from above the card catalogue. - Just for a moment, dear readers. I close in twelve minutes. - Her keys at her belt whistled. - What are you looking for? - Plans of the school. The old ones, if there are any,' Leila replied. - 'We're looking for a backdrop for a film. And the east wing... well, you know... it looks interesting. - The plans? - Mrs Rose nodded towards the glazed cupboard. - 'In the folder "LO3 - 1970s-90s". Just be gentle, because the paper is falling apart. They spread the maps out on the reading room table. Line after line moved before them of corridors, studios, staircases. On one of the sheets, faded by time, someone had drawn a rectangle at the end of the east corridor with a soft pencil: "S-0". The letters were slanted, slightly nervous. Nina swallowed her saliva. - "S-zero?" - She whispered. - 'I've never seen anything like that on the set. There are only rooms 1 to 34 here. Maks leaned in, looking just over her shoulder. He spotted another note in the margin: 'bell test 19:07'. - Who does a bell test after seven? - he muttered. - Is that signed? - He ran his finger over the yellow band of paper. Nothing, just a light smudge of graphite. A short hum shot from the speaker in the ceiling, as if the building had coughed. A chill ran through the library. Everyone froze, listening. The clock above the desk read 19:05. - 'All right,' said Mrs Rose, peering through the door. - 'I've got to lock up. You guys take care of yourselves now, too. And remember: there is no access to the east wing. - 'Sure,' they replied in chorus, and then, as soon as the library door closed with a quiet click, they looked at each other in agreement. - 'If we're going to shoot something that's going to get people moving, it's going to be there,' smiled Maks crookedly. - 'We'll save the frames, and that's it. We don't have to go far. - I'm not stupid to skip tapes. - Leila tucked the notebook away, but kept the sheet marked 'S-0'. - But... to see up close is no sin. When they returned to the ground floor, the corridor seemed even longer, as if the walls were working, drawing them towards the forbidden part. On the way, they passed a display case with archive photos: the 1991 volleyball team was smiling unevenly, and someone had penciled a few names under the picture. Out of the corner of her eye, Nina noticed the date "1972" in the corner of the black and white panorama of the classroom. On the back of the display case, another photograph flashed by: the basement corridor, the board "Technical rooms". A simple thing struck her - above the board hung a small number badge, barely legible on magnification. She pulled out her phone and zoomed in on the photo. S-0. - Look,' she whispered. - This is not just someone's joke. The caution tape wavered, although no draught was coming in from the windows. Behind the door of the 'Renovation' it was dark, but a very thin line of green was burning in a gap near the floor - the emergency light from the emergency exit. Next to the handle was an old button with a metal cover, like in a lift half a century ago. Above it a small rectangular panel was flickering with an LED. - 'It's locked to the electronics,' Leila said. - And the buttons are out of the circuit. Super. Maks knelt down and looked under the door. On the stone floor on the other side was a thin layer of dust punctuated by what looked like the mark of a dragged chair. Or maybe it was just imagination. - 'Wait,' Nina looked around and stretched her hand towards the radiator under the window. A metallic trinket was wedged between her ribs. She tugged carefully and extracted a small brass key on a key ring with a faded letter. The letter was just one, clear: S. - It's no joke,' breathed Maks. - 'It's as if someone left ... He didn't finish, because three short, dry beeps came from the speakers throughout the corridor. Then the bell rang. At exactly 7:07 p.m. A notification came from Nina's phone: a vibration so violent that she jumped up. The screen lit up automatically. "Plan for today - update: Class 2D. Classroom: S-0. Supervisor: -". Exactly right, with a pause, no name. - 'Someone's making a silly joke out of us,' Leila said, but her hands were cool as she touched Nina's shoulder. - It's... it could be some kind of system error. - The system doesn't throw in rooms that aren't on the schedule,' Maks replied quietly. - 'And it doesn't do it the moment we find the key. They swallowed nervously, listening. On the other side of the door something rustled, as if someone had put paper on the desk. The panel above the door handle flashed, jumping between red and green. Then it flashed briefly once, a second time - and froze green. The lock on the door clicked, a metallic sound echoed disproportionately loud in the empty corridor. - 'We don't have to go in,' Nina said, and although her voice was composed, she felt her heart beating faster. - 'We'll just take a look. Literally one frame. She slid her fingers over the cool, slightly rough door handle. She put her hand together with the key, but there was no need for it - the door let go by itself under pressure, as if someone on the other side had gently but firmly unlocked it. There was a whiff of dampness from inside and something else that was hard to name: the smell of chalk, old paint, autumn leaves brought in on shoes, as if the cellar remembered all autumns at once. In the semi-darkness they could see the outline of a staircase descending and a narrow streak of light that, unbeknownst to them, came from the lower platform. At that exact moment, all three phones trembled simultaneously, as if on command, displaying the same message, unsigned: "Entrance unlocked. Room: S-0. Please be quiet." Nina looked at Maks and Leila. There was a mixture of fear and excitement in their eyes, the same mixture that always led them to where there was something to discover. She took a deep breath. Downstairs something rustled very quietly, as if someone had moved a chair away from the table. - One, two, three? - She whispered, placing her hand on the cool metal. And as she pushed the door open wider, they heard a clear, short whisper, coming from the depths of the stairs, as if the school were saying their names one by one.