When the first bell on Monday sounded like an irritated microwave, our school - Kalinowo Primary School No. 14 - woke up as it always does: with the clatter of lockers, the thud of trainers and a chorus of "ma'am!" to the lady on duty. The ground floor windows overlooked a football pitch wet from the night's rain, and a row of poplar trees sang sternly: shoo, shhh, as if they too had something to say. - 'Today we're doing a Sound Map,' said Mrs Trawinska, our journalism club tutor, correcting her orange fish scarf. - Three obligatory points and one arbitrary one. You have a recorder, a list of places and free imagination. This is supposed to be material for Friday's episode of 'School Ear'. 'School Ear' is our podcast. I host it together with Basia and Igor. Basia has an ear for rhythms and can pick out the falseness from across the corridor. Igor edits everything: mutes, trims, adds effects. I ask questions, make enquiries and carry a notebook with a dolphin sticker. We leave the IT lab with the recorder clipped to a yellow lanyard. First the canteen. The lady intendant was scrabbling with a metal ladle at the bottom of a large pot, where something bubbled like mud at the edge of a lake. Spoons clattered against the trays, and in the background the P.E. gentleman called out: "Not barefoot! See that puddle?" - This will make a backdrop for our headlamp," muttered Igor, glancing at the indicators on the display. - 'I love that field effect: spoon versus tray, like a drum. Then we went to the library. Ms Rose was arranging the novelties and whispered: "Shush, books like quiet". The old fluorescent light above the counter buzzed slightly, like a mosquito that can't find its way to the window. Basia slowly ran her finger over the spines, reading the titles, and every now and then she sighed: "Not yet, too much on the list". The third must-see: the gymnasium. Balls were bouncing, the trestle creaked, someone shouted "pass!", and the echo made it "give... ay... ay". I stood in the middle with the recorder straight up to catch the squeak of the hoop. - There was any left," said Igor as we walked down to the changing room. - Something we hadn't recorded yet. Basia looked at the map of the school hanging in a display case by the gatehouse. The red dot 'here you are' indicated us, and zigzags spilled down the corridors. There were two staircases, A and B. Cage A had pots of ferns and an entrance to the secretariat. Cage B... well, that's what it was. Staircase B led to the wing where the old art studio used to be, but now held equipment for festivals and cartons of coloured paper. - Everyone always goes A - I noticed. - Because it's closer to the classrooms. B is as empty as a box of chocolates after a break. - Empty sounds good - stated Igor. - We'll have a clean ambien. Let's go. The B staircase smelled of cool concrete and oil paint. The walls had traces of long-removed showcases. Dust lay on the handrail, the kind that one draws with a finger with satisfaction. The fluorescent light trembled slightly. The light switch clicked, but the light only hissed and took up position like a breathless runner. - 'We record for half a minute of silence,' I whispered. - Then we go. We stood on the mezzanine floor. The recorder blinked a green LED. We could hear the distant life of the school as if through three pairs of doors: muffled laughter, 'eee', 'hm'. Almost nothing could be heard from this cage. - 'Cool,' muttered Igor. - It was as if someone had taken a tape out of a cassette recorder and stopped time. Thirty seconds later, we returned to class. It wasn't until the break, when we sat down at the computer in the studio, that the ride began. Igor ripped the files and put the first one into the program. Waves of sound appeared on the screen, like a green landscape. He clicked play. The canteen sounded as it sounded. The library whispered. The gymnasium bounced a ball. Then Cage B came in, and for a moment there was just nothing on the speakers. A silent nothing. Igor was already about to move the zipper when Basia leaned over and furrowed her brow. - Wait - she hissed. - 'What's that? "Seven." The word was like a blow on the neck. Almost invisible in the wave of sound, almost inaudible. Igor pulled back and turned up the volume. A slow, clear countdown emerged from the noise, spoken in a voice I didn't know. "Seven... six... five..." I felt warm and cold at the same time. - 'It's someone,' I said, although it sounded like I was trying to convince myself. - Someone from above? From below? Maybe an echo from another cage? - Not a chance - stated Igor and showed the diagram. - Here. Silence, silence, silence, and then these syllables are so close to the microphone that you can see the pop. No one else spoke directly into the recorder for us. "Four... three..." Basia swallowed her saliva. - After all, there was no one there - she whispered. - There were three of us standing. There were only walls next to us. "Two..." - Maybe it's some kind of automaton? - I tried again. - An evacuation system? An exercise? - An automaton would speak with a siren or a beep,' muttered Igor, quite soberly, like an engineer. - 'That's someone else's voice. And it's not any of ours. "One." At 'zero' the recording broke off habitually, just as it had begun. And then there was the silence of the B-frame again and the buzz of the fluorescent light. Basia opened her notebook and wrote in large, even letters: "Staircase B - countdown?". She put the dot so firmly that it pierced the page. After lessons I accosted Mr Roman, the maintenance man, who was leaning against the countertop in the porter's lodge and eating an apple, slicing it cleverly into eighths with a knife. - Mr Roman, and Cage B... - I began cautiously. - Has anything... changed there recently? - The railing has come loose on the second mezzanine - he said, as if he had his answer prepared. - And the fluorescent light is capricious. A new one has to be ordered. Why do you ask? - Because we were recording the sounds and... - I stopped. - It's very... quiet in there. - And that's a good thing - Mr Roman muttered. - In silence you can hear what's playing in your head. But don't go there if there's a 'Do not enter' sign. Already know what you want to know? That's good. - He smiled and focused on the apple again. By the end of the day we couldn't stop thinking about it. In maths, the bars of integrals (not true, there are no integrals in our house yet, but bars of operations) looked like waves of sound from our file. In Polish we were reading about heroes who do brave things, and suddenly I felt the white sheet of the B mezzanine pulling at my sleeve. - 'We'll go after class,' Basia decided, which didn't happen often as I usually decided and she reminded me not to forget the audio cover. - Just for a while. And we don't touch anything. We'll just listen. - And we'll set the recording on a tripod - Igor added. - I have a mode, which only catches what's straight ahead. If it's something that happens at a certain time, we might just catch it a second time. When the final bell tossed the students out into the schoolyard like confetti from a tube, the three of us were left, seemingly casually wandering around the upstairs corridor. The secretarial lady was closing the window. Someone was turning off the light above the notice board. Mr Roman was moving a ladder. Cage A was noisy, as usual. B - was waiting. A note hung on the B door: "Attention: do not enter - maintenance work". The door was not locked, but slightly closed. We looked at them for a while. - This is not 'entering'," whispered Igor. - This is 'putting the microphone over the threshold'. - Well, all right - gave way to Basia. - Just don't move away if you have to leave. After a minute we're leaving, it's over. We slid behind the door, like shadow after shadow. The air was cooler. Mazovian terracotta tiles under our soles. The fluorescent light hissed and blinked. Igor set up a tripod on the mezzanine, positioning the microphone pod straight for the stairs leading upwards. I stood next to it, noting down the time and temperature (because Basia said it was important). Basia held her rucksack and pressed a nail skin into her teeth, something she does when she's nervous. - 'Start,' said Igor almost silently and pressed the red button. The clock on my wrist showed 3:07 p.m. The clatter of shoes had stopped in the corridors and the school seemed to breathe like someone who had just put their bags down and sat on the sofa. For the first ten seconds, all we could hear was our own breaths and the distant buzzing of the water vending machines. - Nothing - Basia's exhale moved a strand of hair on my cheek. - Wait - Igor raised his hand. Then it came, softly, like a drop that falls into a bowl. Like a word someone puts next to your foot to see if you notice. - 'Seven,' said the voice. Not from above. Not from below. Not from the side. As if from where we were standing. I felt my heart beat faster, not quietly, but in such a way that I could even hear the blood in my ears. - Six - it sounded immediately afterwards, more clearly. Igor twitched, but the hand holding the tripod was steady. - Five... Something appeared on the wall vis-à-vis me that I hadn't noticed before. There was a narrow, even crack running between two slabs of plaster, as if someone had once stuffed a ruler in there and forgotten to slide it out. The fluorescent light hissed once more, and in that second I had the impression that the crevice was marginally brighter. - Four... - Do you see that? - I whispered, without touching anything, although my fingers itched. Basia nodded in such a way that she almost didn't move her hair. - Three... Mr Roman bolted the gatehouse door from a distance. We heard the metallic sliding of the lock. The corridor was emptying, the smell of chalk and damp jacket hung like a cloud near the ceiling. There were no more sounds other than us and what was speaking to us from close by. - Two... The crevice twitched. Or so it seemed to me. A tiny gust of chill moved across our ankles, like a cat that mushes you with its tail and promptly disappears. Igor, without taking his eyes off the display, whispered: - 'After zero, don't do anything. We look first. - One... The voice was neither threatening nor kind. It was as calm as a teacher checking the attendance list. At the same moment, the LED on the recorder blinked harder, as if it had caught something bigger than us. - Zero. Then there was a quiet, short click in the wall, right along that even crack, and right next to our knees something squeaked, as if someone from inside was slowly moving the lock away.