The night in the Old Station smelled of dust, grease and cold stone. Having turned off the lights in the clock room, Lena walked through the hall, where the echoes stuck to her footsteps like an old placard to a wall. Between mouldy posters and cracked tiles ran arches - arcades that had once led to platforms but now ended in a wall of brick and cement, like sentences without punctuation. She was an archivist with a predilection for what didn't fit in the files. She had a habit of talking to objects in her mind; telling them where they would end up, promising not to forget. This evening she was promising again. The leather case with the keys rattled against her hip as she turned into the corridor leading under the Twelfth Arcade - the largest, the lowest, with a lintel as slick as if it had been stroked by the hands of passers-by for a hundred years. On folding stools lay inventory books: skinny notebooks, bound volumes, a notebook with a green spine that today attracted her like a magnet. It was not on any list. On the spine was an inscription in cursive school writing: "Register of Lintels 1891-1913". Lena swallowed her saliva and opened the cover. No shelf numbers waited there; instead - sketches of arches, dashes of sounds, scratches described with the words "voice of stone, low, clear", "answer at dawn", "do not enter without reflections". Next to one drawing someone added: "Twelve o'clock - sings if one remembers the tone". - Too late for arias," muttered someone from behind her. Lena did not flinch. She recognised John's step by the way he slowed down just in front of her back. The clock restorer, buttoned up to the last button in his apron, held the weight of the pendulum in his hand as if it were a glass with something to spill. - Did you put out the hall? - I have extinguished it. I only left the lamp by the timetable of the fifty-second,' she replied. - This notebook does not exist in the inventory. See. Jan leaned over the sketches, raised an eyebrow. - Lintels? Who was even classifying this? - He picked up a sheet of paper and put his ear to it, as if something could be heard from the paper. - "Do not enter without reflections." What does that mean? Lena closed her eyes for a moment. When she was a child, her Aunt Irene used to make her stop under every door beam and say 'excuse me', as if asking for permission. "The lintels remember more than we do". - she repeated, half-jokingly. She laughed at this until the laughter began to come back to her in the completely silent rooms. - That you have to hear your own return,' she said after a while. - Maybe it's all about the echo. On the wall under the Twelfth Arcade someone had long ago drawn a thin circle in chalk, rubbed with shoes and damp, and a small dot at the top of it, just below the lintel. Lena pushed back the bench and stood in that circle, uncertainly. The bricks breathed cold. A cable from an old light dangled from the ceiling, the trembling of the bulb muffled by dust. A phrase kept ringing in her mind from her closed notebook: "Twelve o'clock - it sings if you remember the tone". - What are you doing? - Jan already knew he wasn't going to stop her with the usual 'not allowed'. He leaned the pendulum against the wall and pulled a small steel camertone fork from his pocket. - It's for H, from the clock in the main hall. It's missing its lower arm, but it still sounds. Lena picked up the camertone, put it to her wrist, tapped her finger and pressed the vibrating metal fork against the stone under the lintel. The sound was crystalline, as if a drop was falling into the glass. In the silence of the corridor, it spread so that she could feel it in her teeth. And that's when the arcade responded - at first almost inaudibly, like the burbling of an old cooker, then more distinctly, until finally there was something in the wall that shouldn't have belonged to anything: a deep, THICK note that wasn't a sound, but a place. The air beneath the lintel became heavier, the cold receded a step, as if someone had warmed their hands over a blowtorch and pressed them against the wall. The smell of wet earth and lime trees after the rain rose from the joints, although it was half a street from the station to the nearest tree. Jan moved back half a step, but not enough to stop seeing. - 'One more time,' he said, quieter than he thought. Lena slapped the camertone against the edge of the bench, as gently as if asking for attention, and put the metal to the stone again. This time the sound spread in an arc like circles on water. The darker streak between the bricks flared like skin that had been touched by the sun. For a blink of an eye they saw something in the wall: not a corridor behind the wall, not a soggy brick, but a surface that reflected the light not as it should. Not like a mirror - more like an eye. - 'It's not safe,' Jan muttered, but he sounded like he was talking to himself. - 'If that had slipped - he indicated with a gesture the cement tin, the conservators' long-standing fixes - we would have had half the archive on our conscience. Lena did not let go of the camerawork. She pulled from her memory notebook the words written by someone in a feverish handwriting: "do not enter without reflections". So she picked up the leather key case, the same one that held all the door faces of the building, and shook it lightly. The metallic clang bounced off the bow and came back to her like a hand - not identical, just half a tone lower, like an echo from another room. - Can you hear it? - she asked. Jan nodded. - It's not our echo. When the answer came a third time, it came with more than sound. Beneath the Twelfth Arcade, just inside the dot in the chalk circle, dust rose in a lukewarm swirl, as if someone had stepped through a non-existent gap. The extinguished bulb on the cable rocked without a breeze. A quiet tone seeped out of the wall, which had a taste - salty, like leather after sailing - and a smell: of the sea in a place where the sea had never been. Lena caught a glimpse of something that could not be encompassed by the gaze fully: two horizontal streaks of light appeared in the shiny surface, as if horizons one above the other. On the lower one, one could see patches of grass and domes as if made of glittering shells; on the upper one, a staircase in the sky, suspended between two unsupported columns. The stone adjacent to the wall trembled under one's fingers so gently that it could be mistaken for a pulse. - If this is... - Jan interrupted because he was at a loss for words. Lena wasn't even looking. Out of the corner of her eye, she noticed that his fingers, usually calm as tips, were trembling. In the Register, which she only managed to trace halfway through, the notes were getting voluminous and clumsy at one stage, as if the writer couldn't keep up. "Twelve o'clock, the night of the equinox:" she replies in a third tone. Remember the wheel. Do not stand alone. The lintel learns. The lintel is watching." - that much she managed to read before the paper rustled in her hands from the dampness of the air. She didn't try to understand everything at once. She took a deeper breath. - Let's do the reflection together,' she suggested. - One, two, three. At the same moment, they shook the metals: she with the keys, he with the cameramen, this time attached not to the wall, but to the blanks with the numbers of the clocks. The sounds interlocked like cogs. The arcade made a sound that resembled an inhalation. The surface beneath the lintel became simultaneously rigid and liquid; the glaze in the brick took on a depth, like water over a bottom that is receding. From within what had just been a wall came a thud - three times, evenly, at intervals as measured as if a metronome had clicked them out. Then a second, shifted a little, like an echo half a step late, like someone trying to imitate but not yet knowing the rhythm. Lena moved her face close enough to see her own reflection. She wasn't there. There was only darkness and two horizons. She was already about to step back when the surface moved slightly, like a curtain on a draught, and something from the depths came close enough to distinguish the outline. Not the shape of someone's face, not a figure. Rather, a presence that drew one's gaze into the depths until one's temples began to ache from walking that gaze. - 'Lena,' Jan said, but his voice trailed off as a whisper came from that direction, not from the corridor, not from the Old Station. He spoke her name, clearly, softly, in exactly the same timbre with which she spoke to papers and old things. The surface flashed, and the dot in the chalk circle flashed, as if someone had touched it with a finger from within. The lintel lifted by a hair, unnaturally springy like a collapsing cushion - and before Lena had time to withdraw her hand, another word flowed from the other side, shorter, heavier, much closer than a moment ago