September Toruń smelled of wet brick and cool metal, and the river twisted under the bridge like a dark film. Lena stood in the courtyard of the closed planetarium on Zbożowa Street, clutching in her hand a round brass object that her grandmother Irena had left her. The watch lay against her skin like a promise, heavy, tame, with a thin chain and an engraving on the back: When time stumbles, open your eyes. - 'I can't believe we're really coming back here,' muttered Oskar, wiping his dewy glasses with the sleeve of his sweatshirt. - 'After the last time, I'm still dreaming of the stardust that circulated under the dome. - 'We didn't have a reason last time,' she replied, although a nervous spark twitched at the corners of her mouth. - Now we do. The reason lay in her grandmother's scented paper notebook. Among the diagrams and notations, which looked like a combination of diary and physics notebook, she came across a date and time marked with a serious triangle: Night of 29-30 September. Leap second. Planetarium-pendulum. An exact notation of the coordinates of Toruń, a cross in place of the dome and a few sentences too simple to disregard: Count when the world stops. Don't touch the cable when it buzzes. Don't run away if you see a light in the wrong place. Lena didn't like the words 'don't run away'. She was seventeen, fierce and stubbornly aware that Grandma Irene wouldn't leave her something that was just an elaborate puzzle. And yet, as the whole school filled back up after the summer holidays, and she had mechanical conversations about matriculation and plans, the watch in her pocket ticked differently. Sometimes at midday it sounded like rain against hard tiles. At midnight it emitted a single, deafening whisper. Once, in the corridor, the hands stopped at 12:59, then twitched and moved one dash further than they should have - as if trying to learn a new step. The planetarium's extinguished windows reflected the streetlights. The building had been officially 'undergoing refurbishment' for months, which in practice meant that no one had a head for it. The door, which was still familiar to Lena's childhood, creaked open. They didn't break in; in old places something is often left unlatched out of habit. They walked along a corridor that smelled of nails and dust from the star projector, passed by a display case with a photograph of children in synchronised wonder, and then went under the dome - a great white sky on the ground. - Have you got it? - Oskar held out his hand. He glanced at the watch, but didn't touch it, as if he was afraid the object had a mood of its own. - Leap second... Is this even going to happen? - Grandma didn't write about what's on TV, she wrote about what's here - Lena pointed to the ceiling. - What counts is what we count. In the middle of the dome, where the Foucault pendulum used to hang, someone smarter than the city's maintenance office had concocted something that didn't fit into any instruction manual. A metal ring in which two glasses were embedded: one milky, the other as if made of very thin ice. There were braided wires coming off the ring, but they did not run to any socket; they ended in a box bolted to the foundation, on which Grandma Irene had left her small, slanted handwriting: Resonator. Treat it like a heart. Do not overload. A switch is not everything. - "It's not everything... - Oskar read half-heartedly. - Sounds like her. They looked at each other. Oskar by nature rolled his eyes when something smelled of exaggeration or theatricality - and yet today the pocket of his oversized sweatshirt concealed a charged torch, a field meter, a nimble powerbank and a bundle of crocodile-ended wires. Lena had a notebook, a watch, a bent tram ticket and her grandmother's letter, which she had carried with her since the day of the funeral, already crumpled from reading: Lena, in my cases they didn't listen to me at first and then asked me how I did it. You listen right away, because we don't have time. They spread things out on the floor with Oskar. The dome seemed to breathe, their breaths sounding like books being moved. From outside, the city rumbled again and again as the train passed, as if to remind them of the constant presence of the tracks - lines that lead somewhere, if you can climb them. - 'Okay,' Lena breathed. - First things first. She opened the watch. The dial was classic, but two extra dashes between seconds three and four were immediately striking. In the centre, near the axis, someone - probably her grandmother - was scratching with a thin screwdriver a tiny mark similar to a cross on a map. From the bottom of the envelope, a tiny pin could be slipped out, which slid perfectly into the Rezonator's socket. It was as if everything was designed to belong together. - How is this supposed to work? - Oskar asked more quietly than he needed to. - 'There are theories, you know. Space-time, gravity, loops... But here we have... this. - He touched the ring with his finger and it twitched. - Warm. - 'Grandma wrote that mechanics is the language the world answers to the patient,' Lena said. - For now we ask politely. They turned on the electricity. Not any city power supply - The resonator was autonomous. A faint amber light seeped through the milky glass. The pendulum that should have hovered over the centre was now a short, heavy rod that didn't so much hang as stick, like a compass needle in the thick syrup of time. - Check,' Oskar handed her the phone. - One minute to midnight. - Until midnight according to them - Lena tapped the envelope with her fingernail. - According to us, one minute and one second. It got quieter under the dome, as if the rain outside felt uncertain. The town clock in the old town gave out the distant, muffled sounds of a full hour. The hands on Lena's watch moved steadily, but what was to come was not steady. It was to resemble a breath just before a run. - If this... if something really happens - Oskar swallowed the dry word - where will it be? Lena opened the notebook. Written in thin pen, the instructions were specific: Next to the ring, set the date. The right scale is days, the left scale is years. Don't turn it the other way round. Don't start more than twenty seconds before. Do not touch the pendulum when it starts to tremble. The scales under her fingers clicked softly. Lena set the date of her grandmother - not a birthday, not an important event, but a perfectly ordinary day fifty years ago, June 1973, the middle of the night. Oskar did not question this combination; there was something in his gaze that made him think it was no coincidence that in this town and in this family the nights could be thicker. - Thirty seconds,' he said. - You still have a choice. - I always have - Lena smiled briefly. - That's why I'm here. She squatted by the box. The metal was rough, the skin of her fingers going into the microscopic cracks of age. She leaned over the engraving on the back of the watch and once again read the words she knew by heart. Her eyes grew accustomed to the amber light, the darkness just beyond seemed thick and close, like a theatre just before the curtain rose. - 'Ten,' counted Oskar. - Nine. Eight... The watch ticked like a small instrument. The air trembled hesitantly, softly, like the blades on a bird preparing to fly. On the milk glass of the Resonator, a thin grid appeared, at first almost invisible, then increasingly clear, like a drawing emerging from under the water. It was the layout of the streets. Lena recognised the course of the Vistula, the great patch of the old town, but something didn't add up: the bridge she knew from the daily trams was missing, and where the modern centre now stood, there was only an empty, dark spot. - 'Five,' whispered Oskar. - Four. Three... The pendulum trembled. Not like ordinary steel, but like a string that heard its own note. A barely perceptible wave coursed across the floor beneath their hands - too subtle to be called a shock, too distinct to be ignored. The smell of dust changed to that of ozone and wet leaves. Lena felt the hair on the back of her neck rise a millimetre. - Two. - Oskar... - she whispered. - If on the other side... - Don't finish - he said. - Just watch. - One. The sound of the clock disappeared. For a fraction of a moment, Lena got the impression that everything had ceased to exist in precise, separate things and had become one - air, light, warmth. The seconds hand hesitated. Instead of jumping to zero, it twitched higher, into the space between the dashes, where it had never had a place. A number shone on the dial that no programme had anticipated: 60. The resonator sighed and glowed harder. The milky glass no longer showed a map, only movement. Streets they didn't know shifted like in an old film, and there were people - silhouettes with sharp collars, long coats, liveried signboards whose letters weren't entirely unfamiliar to them, yet sounded different. A brief flash blossomed in the celadon sky, not like lightning, but like a crack in the crystalline ice. The pendulum stopped in mid-air. It did not descend. It stood, vertical like a finger at the mouth commanding silence. The air under the dome thickened. Lena, holding the watch, felt the chain tighten slightly, as if someone on the other side was holding the other end of it. - 'Lena,' someone said. The voice did not come from the loudspeaker or the corridor. It didn't sound like a memory of her grandmother, although there was a similar shiny claw in it. He was here, in this moment, saying her name with a soft 'e', like before. - Can you hear me? Oscar looked at her, and his "can you hear it?" was just a gesture, because he could hear it too. The amber light passed into a cool glow. A lattice of milky glass opened from the inside like an eyelid, revealing a densely woven window onto something that should not exist in the middle of the night. At the other end, the early morning bloomed, bright with the sharp, low hue of the sun. A horse with a harness like from a photograph was breezing along the cobbles. There was no new bridge over it. In the display window stood a radio larger than a suitcase. And a girl, in a dress with navy blue peas, put her hand to the glass on that side, in the same place where Lena held her watch. - 'Time has stumbled,' the girl on the other side said quietly, but her voice carried under the dome clearly - as if she was speaking to them through metal. - 'You've only got a moment before it's back to an even stride. Lena felt everything that had been a lesson and a theory so far come together as a decision. The resonator hummed softly, the pendulum continued in unnatural stillness, the watch chain tightened like a string. The number 60 on the dial pulsed slowly, like a heart under an eyelid. - 'If we go in...', Oskar began, but didn't finish because the sound of a key in the door came from the corridor. Someone else was in the building. Someone who didn't like uninvited guests. A fine dust fell from the ceiling, like silver rain. The milky glass trembled and cracks resembling a map of rivers ran across its surface. - 'Decision now,' said a voice from the bright side. The girl's hand clung to the glass. - 'Either you stay or you run. Just don't stand in the half step. Second 60 flashed, as if it wanted to disappear. The pendulum vibrated. The handle of the dome door dropped with a heavy, too-loud click and someone's shoes began to measure the distance to them on the stone steps.