Since the old ferry terminal closed, the wind had been learning to play on its railings. The metal stairs groaned like a double bass, and the empty halls reflected the sound of heels as if someone was walking right behind. It was colder than usual on a Friday evening; the smell of salt and grease wafted in from the sea, and a thin mist pressed in through the unsealed doors. On the wall in the main hall stretched a mural - 'Map of the Baltic', as the slightly tilted inscription beneath the ceiling proclaimed. No one had touched it for years. Lena Stańczyk slipped down the sleeve of her sweatshirt so as not to dirty her wrist with paint brightener. She moved the brush carefully, millimetre by millimetre, bringing out from the dark layer something that looked like the blurred contours of a fairway. Just a month ago, she would have said that none of these community projects made sense - she was finishing the second semester of her graduating class, and here she was being told to scrape the walls. But the mural had something about it that argued with her mumblings about the uselessness of looking at the past. It was strangely accurate. Not just the islands and depths, but the small marks that usually hide on specialist maps: buoys, landmarks, constrictions of currents. Whoever painted it really knew what they were doing. - Do you think it's a lighthouse or just decoration? - Maks asked, standing next to it. He was wearing a baseball cap on his head and those perpetually crumpled headphones that dangled from his neck like two sad jellyfish. He fired up the torch on his phone and shone it at just the right angle so Lena could tell the difference between paint and dirt. - 'A lighthouse from 1938,' she mumbled, glancing at the tiny triangle marked point. - 'See, here's the description, just painted over. "Hey..." - she stepped back, rubbing her finger. Painstakingly and thinly written letters began to emerge from under a layer of grey-green paint: 'Transition point'. Maks whistled quietly. - Sounds like an invitation. - Or like a joke,' she concluded. - 'There hasn't been anyone here for a decade. The lobby was dominated by the yellow light of the halogen they had hung earlier under the VIP balcony. It gushed warmth, but did not disperse the shadows in the corners. The Terminator, as the doorman, Mr Zegota, ironically described it, at which every chair had names and stories. Today he left them alone; he said he preferred to keep an eye on the gate because "at least there is something going on there - the foxes are coming". He promised to return in an hour. - Let me see that radio - Lena asked, putting down her paintbrush. From the corner Maks brought a metal box on springy legs. A worn-out radio, found in one of the technical rooms. The plate was engraved: "For training purposes. Do not connect to mast". Instead of a mast, there was a makeshift antenna made of copper wire, strung between the balustrade and the coat rack. - 'Look,' said Maks, switching on the device. The scale creaked, the pointer moved and stopped near a frequency that no one used anymore. The noise rustled like the breath of waves under the concrete platform. For a moment it was just that. Then there was a sound that resembled nothing familiar - not a voice, not a screech, not music. As if someone was sifting glass. Lena felt the skin on the back of her neck get goosebumps. - Turn it off? - Wait. - Maks turned the knob, and the noise suddenly settled into a rhythm. They heard a series of numbers, spoken in a calm, colourless tone: - Five four degrees three zero minute N, one eight degrees three three minute E. - Silence. Then a repetition, no change. Silence again, as if the radio had taken air. - 'These are the coordinates,' said Lena. - Exactly here. - She smiled uncomfortably. - We have our own weather station with humour. Maks was already rummaging through his phone. - Exactly here - he confirmed after a moment. - The main hall. - He raised his eyes. - OK, let's call a spade a spade: this is creepy. Lena remained silent. She went back to the wall and moved her hand over the lettering 'Point of Passage'. The edges of the letters were sharp, felt under her fingertips as if someone had carved them into the plaster rather than painted them. In the halogen light, the paint across the strip along the rim of the wave shifted a fraction - not the way a liquid does, but as if the image had imperceptibly changed frame. - 'Did you see that again? - Maks asked in a whisper. He didn't mean to, but the whisper came out naturally to him; something in the hall told him to speak more quietly. - Yes. - Lena swallowed her saliva as she watched a flap of plaster break away in the corner, though nothing had moved there. - Say something out loud. Anything. - Er... - Maks hesitated. - The fifth letter of the alphabet is E. - His voice reverberated in several thin layers, but instead of the usual reverberation Lena heard a flicker, an acoustic signature that did not apply to this space. The air thickened as if before a storm. The radio whispered the coordinates again. Longer this time, as if the device was afraid they didn't understand. The pointer on the scale twitched and stopped exactly in the middle. Under the halogen, the shadow of the ropes that used to hang from the ceiling trembled. And then they noticed something that had previously escaped their attention: a thin crack ran along the lower edge of the mural, just above the skirting board. Light, almost invisible, but perfectly straight - it started at the letter 'P' and ended under the white seagull painted in the corner. - 'That's not a scratch,' Lena said, crouching down. - 'It's grouting.' - She undermined with her fingernail. The plaster gave way a millimetre and fell back into place springily, like rubber. - 'You mean to tell me that the wall has... skin? - Maks took a step back. - I don't like the direction this is going. - Calm down. - Lena felt her heart beating faster, but curiosity was bending all the needles in her. She wiped her hand in her trousers and tried again, more carefully now, at an angle. Under their fingers, the surface of the mural was warm. Warm, even though it was cold all around. A muffled bang came from the distance, as if someone had dropped a container on the quay. The hall responded with a tremble in the railing and a slight thud in the floor. The halogen flickered and dimmed once a second, like a battery saver on a phone. Maks automatically moved the radio closer. Then the voice that had hitherto recited the coordinates changed. It didn't say names, it didn't take on any colour, but the intonation relaxed so that it resembled human speech. Lena felt it in her stomach. - Can you hear it? - Maks whispered. - As if... as if someone was switching to our way of speaking. - Maybe it's testing,' replied Lena, uncertainly. - 'Or... it's an echo. - She wanted it to sound rational. It didn't. She rested her hand more firmly on the 'Baltic Map'. The paint under her fingernail slipped a little. The wave that someone had painted across the width of the wall seemed wet for a second. The air that oozed from the very surface of the mural smelled of wet pine and ozone. Like after a storm over a forest, except that they were separated from the nearest trees by a kilometre of concrete, asphalt and iron. - Lena. - Maks said it the way you say 'stop' to someone who doesn't notice they're walking directly into the roadway. - I know - she replied, although she didn't know. And then the 'Baltic Map' did. Not by much, by a hair, by the thickness of a thread - she stepped back. As if she had stretched the surface one breath further from reality. The scratch under the slat shook and for a moment became dark green, so deep that Lena imagined you could slip your hand in there and feel the current under your fingers. The radio beeped, overdriving, and then clattered three times, as if the operator on the other end - whoever he was - was hitting some metal plate. One, two, three. After a moment it was answered by something on this side: a single deafening sound, from inside the wall. Lena and Maks exchanged glances. - 'No... we're not opening, are we? - choked out Maks, turning down the radio, although it didn't matter. Lena felt like saying, 'Of course not'. At the same time, every fibre in her body suggested the image of her own hand sliding into the cool, springy crack. Reason was momentarily lost to whatever was reaching out to her from within. Instead of answering, she removed her rucksack, took out a chalk, the same one she used to mark the damaged sections of plaster. With a trembling line, she drew an oval around the 'Point of Passage', just as she used to do in maths when she marked things she was curious about in her notebook - the other children would put dots, she would draw orbits. The halogen light trembled as she completed the oval. The chalk whined across the plaster, as if she had run over a sheet of ice. The oval glowed softly, at first like the reflective paint of the road, then brighter and brighter. A fine dust sprinkled from the installation suspended above their heads, from which Maks sneezed. - 'Someone please explain to me,' he said, wiping his nose with his sleeve, 'why the chalk is glowing. Lena had no answer. The oval pulsed in a rhythm that could be correlated with the tapping on the other side. One, two, three - pause. One, two - pause. Like a code being punched into the hull of a ship. - A feedback signal - she muttered at last. - You know how you learn to translate foreign languages bare, without a dictionary? You find the fixed points. - We don't learn the language. We teach the wall to count. - Maks looked at her hands. - Lena... At that moment the halogen went out. All that was left was the pale emergency light by the escape door and the faint glow of the chalky oval. It drew a chill from it, the kind of clean, dry chill like in a server room or a museum where they guard the works more than the people. The radio snapped and sounded different - as if someone had turned the knob and dialled their frequency for good. However, they no longer heard the coordinates. They heard two words. Spoken in correct Polish, without an accent, with perfect calm, in a tone that came to Lena's mind when she thought of attentive teachers. - Are you ready, Lena? - asked the voice from the radio, leaving no doubt as to whom she was speaking. Maks's head drooped, as if someone had cut the muscles under his neck for a moment. - 'You don't have any accounts on those weird apps where bots suddenly speak your name, do you? - He asked without conviction. - No. - Lena felt that this should have terrified her. Instead, an impulse pulsed under her skin: at once fear and something very much like joy. Since her swimming coach had told her she had a 'good start', she hadn't felt such tension at the moment just before the jump. - But I... I think I know what needs to be done. She walked up to the wall. The chalk oval rippled like a ring on calm water. The crack at the bottom was filled with a dark flash that reflected not the halogen farfetches of the outside world, but a different set of lights - green, cool, punctuated by something akin to aurora. The air rustled like a train pulling into a distant platform. - 'Don't do this alone,' Maks said quietly, and without a word he grasped her wrist. His hand was warm, dry. In that moment, Lena felt the band, which had been tight as a string for an hour before matriculation, suddenly snap inside her and become flexible: she was not alone here, not yet a decision pressed to the ground. A whisper came from the radio: - Now. The wall let out a breath of cold air so violent that the halogen killed once more, like a heart on film after defibrillation. The painted seagull moved its wing. The oval brightened and the chalk sprinkled bright dust like snow. A crack opened a hand's width away - beneath the soft, springy membrane a different chill, a different smell, a different kind of darkness gripped them. From somewhere far away a metallic chant reached them, like a high-voltage wire on a winter morning. Lena reached out her hand, not yet touching, but already feeling a slight tingling, like with a CRT screen. A crackle came from the radio, as if someone had taken off the receiver in the next room. Three beats. Silence. Two beats. And then - transmitted more clearly than before - a quiet sound like breathing....