As evening fell, the Central Station smelled of metal and salt. The hiss of braking trains mingled with the shriek of seagulls flying over the tracks, and the wind ruffled the flag on the masts so that the distinctive clacking of the stiff material could be heard from time to time. Lena liked this moment of the day: the lights of the lamps would turn on unevenly, as if someone were testing them one by one, and people would hurriedly stop talking loudly and start whispering. At such moments, the city stopped pretending to be a great metropolis and was more like a port that knew too many old stories. Grandma's shop was located right next to the side entrance to the station. The signboard, remembering the days when the bell in the church on the hill tolled flush with the town hall clock, bore the embossed letters: "Above the Clock - Repair and Tuning". Inside there was the smell of mechanism oil and old wood. On the walls, clocks hung in a row: pendulum clocks with heavy brass lenses, mantel clocks with porcelain dials, click-close pocket clocks in silver envelopes. Each ticked differently. All you had to do was close your eyes and the sounds would assemble into a complex melody. - 'Watch this,' said her grandmother, placing a pocket watch with a delicate rosette engraving in Lena's hand. - It always stops at nineteen seventeen. I can't get him to do otherwise. Take it with Oscar to the archives, it is said to have belonged to the head of the station a hundred years ago. You might learn something. Oskar turned up a while later, smelling of rain and spray paint, with a skateboard under his arm. He had bright hair that perpetually fell into his eyes, and an energy that no room could contain. - Watches again? - He rolled his eyes, but smiled at the sight of the rosette. - Nice. And what, I'm supposed to do security when it starts ticking backwards? - He's already doing it,' Lena muttered, putting the watch to her ear. Indeed, instead of the usual sequence of ticks, the mechanism seemed to go back a fraction of a second and then catch up, stopping at 19:17 each time. The city archive, in the basement of the former post office, was semi-dark and cold. Shelves bowed under the weight of binders and boxes of labels written with a careful, slanted hand. Mrs Virginia, the custodian of the collection, still remembered the days when the station had a baggage carrier with a cap that covered his ears. - 'This watch was a deposit,' she said, slipping them an envelope with a yellowing photograph. - Only this was attached to it. The photograph was black and white, but in a strange way 'cold'. It showed an arched platform, with the number '0' painted on a cast-iron column. Above the arch of the brick walkway, someone had drawn a starfish in chalk and written the date in it: 12 August. The moon shone in the corner of the frame, although the photograph was taken in full view of the lamps. And on the bench, right next to it, was a pocket watch identical to the one in Lena's hand - the hands stopped exactly at 19:17. - Platform zero? - Oskar raised his eyebrows. - After all, there is no platform zero. - 'There isn't now,' Lena corrected quietly, feeling something tighten in her stomach. - 'But that archway... Have you ever seen the walled-up passage by the fifth track? It looks exactly like this. Mrs Virginia shrugged her shoulders. - The station has been redone so many times that the plans get lost on their own. However, if there's something standing in your way, it's certainly not me," she added and winked at them, as if she wasn't talking about papers at all. They left there with a pocket watch, a photograph and a strange feeling that neither one nor the other knew how to name. The sun was already going low, and the air had that transparent tint when the colours seem a little sharper, as if someone had turned up the contrast. Above the roofs of the station hall under renovation, the moon was rising - almost full, like a silver coin suspended on a transparent thread. - 'It's twelve o'clock today,' Oskar remarked. - And seriously don't say it's a coincidence. Lena glanced at her watch. The hands twitched and stood at 6:51 p.m. - If we have to check something, it's now. The corridor leading to platform five was avoided by everyone who didn't have to go through there. It was too cool in there for a summer evening, and the tiles on the walls had cobweb-like microcracks. Coal dust was collecting in the corners, which had no right to be here anymore for years. Around the last bend, the corridor widened into a small alcove. And right there - instead of a walkway to the platform - a brick wall rose. Smooth, polished with hands that had once touched it out of curiosity. Someone, maybe a long time ago, maybe yesterday, had drawn the same patterns on the bricks with chalk as in the photograph: a starfish, the outline of a column, and hundreds of small dots arranged like on a map of the sky. At eye level, in small letters, was the sentence: 'Bus stop only open when full'. - So what, we're supposed to stand here until tomorrow? - whispered Oskar. - Or until the next epoch? Lena crouched down by one of the dots. The chalk was fresh, still clumpy, as if someone had merely touched the surface and walked away. She moved her fingertip across it. - Do you hear that? At first she thought it was the sound of her own heart. But no - it was something else. A gentle, almost imperceptible trembling, as if there was a wire stretched deep, deep, in the wall, on which someone had run a string. The wall muttered quietly, too regularly for it to be a coincidence. Oskar picked up his phone, switched on his torch and ran the light over the bricks. The chalk reflected faintly, and metallic pollen shimmered in its particles. - It looks like someone wrote it with particles of... I don't know... something that glows in the ultraviolet. - Sometimes my grandmother wrote numbers like that on clock parts - Lena didn't raise her voice. - To know what went with what. And she always used a special chalk that reacts to moonlight. Oskar snorted. - Really? - But as he stepped back and the corridor light dimmed unluckily, for a moment a pale blue sheen fell through the arch of the window grille onto the wall. The moon, which had leaned out from behind the rooftops, cut through the space, and the chalk dots trembled and lit up like faint fires. Lena pulled out her pocket watch. Inside, everything went quiet for a split second, as if the room had held its breath. The hand of the second hand twitched, moved back, jumped forward and stopped again. 19:12. 19:13. The wall trembled and, at the same moment, a choked voice came from the old loudspeakers high up in the ceiling, which for years had only served as seats for the pigeons. - Attention, travellers... - the signal was cut by a crackle. - Special train to... - crackle and noise again. - Departure from the platform... zer... - The voice stopped as suddenly as it had appeared. The corridor grew colder. The air took on the smell of ozone, like before a storm, and something else - resin? Lena felt she had goosebumps on her forearms. Oskar pressed his shoulder blades into the wall and his torch twitched, drawing uncertain circles of light. - 'Okay,' he said slowly, and his playful tone disappeared. - 'What if it's not a prank? If it's... you know... some... thing? - Then we'll be the first," Lena replied. She herself didn't know where she got this calm from. Maybe from the ticking all around her, which suddenly became coordinated. All the clocks she had heard all her life were now falling into one clear sequence. - See. She pressed her watch against one of the dotted figures on the wall, as if matching it to the outline. The metal was cool but unpleasant to the touch. The rosette engraving trembled, as if responding to something invisible. The minute hand moved two teeth. 19:15. - 'That's silly,' muttered Oskar, but he didn't look away. - Because I can feel it. Like in your ears... you know, that high-pitched squeal when you press on the old CRT? That kind of tension. - I feel it too,' Lena whispered almost silently by now. - And something else. Like... someone calling out. The lock on the door to their right - the old metal one leading to the technical room - moved slightly and sizzled. Above them, the speakers buzzed again. The moon shifted and the bright glare fell straight into the middle of the starfish. Even the dust swirled in a peculiar way, forming a spiral. 7:16 p.m. The second hand began to tremble, but it did not move smoothly. The wall on which the watch rested began to... soften. Lena couldn't have described the phenomenon better. The bricks, hard as ever, felt as if someone had put a thin layer of water on them. The light from the lamps reflected in a blur, and the chalk dots flowed in indistinct streams. - Len... - Oskar touched her elbow. - See. In the centre of the starfish appeared something that at first could only be an illusion - a vertical streak of darkness, thicker than the surrounding gloom, like a shadow standing for itself. Out of this streak came a breath of cool air, smelling of damp wood, some kind of ancient forest, perhaps a wet platform after a rainstorm. And then, although there was no hole, they heard a distant, very clear sound: the swish that a train makes when it crosses a bridge. - It's absolutely... - Oskar didn't finish. The torch on his phone went off without warning. The darkness had thickened, but it was not uniform. There was a cool, silvery glow emanating from the centre of the starfish, as if another space with a different air stretched out behind it all. 19:17 The pointer clicked into place with a quiet click. The clock suddenly heated up, as if someone had lit tiny coals inside it. Wall sighed. There was no other word. The bricks became completely liquid for a moment. - Attention, travellers - a voice rang out, more clearly this time, as if from very far away, but still. - Special train to... - the word broke, as if bitten through. - The entrance to the track... Lena took a step closer. She didn't have time to warn Oskar not to touch when he - faster than he thought - reached out his hand. His fingers plunged into the surface as if in cold water. The wall accepted them without resistance, and on the other side something brushed his skin - not like an object, more like a wind carrying with it the distant echo of someone's footsteps. They both held their breath. A clatter sounded from within the streak. Single at first, then even, like a beat - metal against metal, distant and yet frighteningly familiar. The light on the other side changed to a deeper colour, falling into purples. Beneath the surface they could touch, a flash outlined itself - long, narrow, growing, like the headlight of an approaching vehicle. - It's coming in. - Oskar said it silently, but Lena read his lips. - Lena. - Someone whispered her name on the other side, clearly, in a whisper that sounded right next to her ear, even though no one was there. - Don't be late. Above their heads the ceiling trembled. Somewhere further down in the station a regular, real train honked, and the echoes blended with what was coming from the wall. The starfish glowed more sharply. The clock in Lena's hand rattled and began ticking anew - but this time each tick reverberated in the wall like a wave. - Are we going in? - Oskar looked at her. There was a narrow light reflected in his eyes that grew and grew until it became something that could only belong to the front of a speeding machine. Lena tightened her fingers on the engraved rosette. She took a second step. The surface gave way, a chill shrouded her skin like mist at dawn, and from inside she heard something that sounded like a long, drawn-out whistle note, just before....