In Brzeziny, a town smelling of lime trees and baked bread, the market square was surrounded by townhouses with colourful shutters, and the town hall tower reigned over everything. Its clock had stood at 12:07 for years, as if someone had stopped time in the middle of the day and forgotten to turn it on. Adults got used to it, children too, and tourists took photos and shrugged their shoulders. Only Zosia was gnawing at it like a crumb in her shoe. She was eleven years old, her hair perpetually slipping out of its braid and her pockets full of pencils. She liked puzzles and things that didn't want to be understood straight away. That day she came to the library under the tower, where Aunt Hela worked, to help look through old newspapers before the school fair. Leon, her cousin a year older, came with her. He thought the smell of old books was something like rain on a hot day-first strange, then pleasant. - In the attic there is a box with the yearbooks of the Voice of Brzeziny" - said Aunt Hela, wiping her glasses in the hem of her jumper. - Watch out for the dust and the beams. And don't lean against the window because the slider is jammed. The attic of the library was a realm of dust and sunshine that sliced the air with narrow rays. Zosia drew the air in deeply. It smelled of paper, rosin and something else she couldn't name-like when you unscrew an old paint can. - Can you smell it? - she whispered to Leon. - Like... a piece of the storm? - He whispered back and rolled a box of newspapers into the middle. For a moment the letters flashed before their eyes: headlines about the harvest, about the school theatre, about the tower clock stopping 'for technical reasons' in 1959. Zosia raised her eyebrows. Technical reasons sounded boring and vague at the same time. - 'Technical,' she repeated, running her finger over the lines. - What if something technical has a whimper? Leon grunted and leveled the stacks. Then he came across a drawer that Zosia hadn't noticed. It was wedged into the side of the wardrobe, thin as a notebook and with a brass knob bitten by the teeth of time. - 'Look,' Leon said, and his eyes shone. - A drawer that pretended it wasn't there. They had to pull it together. It rasped quietly, as if something long unpulled finally agreed. Inside lay a wooden casket the size of a hardcover book. The lid was decorated with tiny stars and lime leaves, carved with such precision that it made you want to stroke it. - 'It belongs in the library,' muttered Zosia, cautious by nature, but her hand slid the lid up by itself. She took it off thoughtfully, as if she were opening the door to a room where someone might be sleeping. Inside, on navy blue velvet, lay a pocket watch on a silver chain. It had a plain case with a thin moon engraved on it and was missing one hand. There was an hour hand and a second hand, but the space left by the minute hand shone empty. Beside the watch was stuck a small glass vial with a bit of glittery sand and a folded piece of paper, thin as a leaf. Zosia held her breath. Leon pulled the vial out carefully, as if he was afraid the sand would settle upside down. He shook it. The grains hovered in the middle for a moment, as if they had forgotten where the pit was, and slowly sank. - The sand that forgets - he whispered, amused and intrigued. Zosia unfolded the sheet of paper. The handwriting was neat, but the letters had something cursive about them, as if someone had written while riding a train: "Don't turn your watch with your back to the window in a north wind. Write down the hours you hear. On the 13th look for the stairs." - What do you mean "write down the hours heard"? - Leon glanced at the watch, which was ticking quietly, although no one was winding it. - And why "on the thirteenth"? After all... At that moment a draughty blast sounded. The attic window, the one with the jammed slider, vibrated and rattled against the frame. The air thickened, and a woman's blanket of dust danced in the sunlight. Somewhere far away, in the market square, someone whistled a tune from a merry-go-round, and the bells at the candyfloss stall buzzed like silver insects. Zosia turned her watch over on her hand. The hour hand ticked uncertainly between twelve and one. The seconds hand moved smoothly, but every few turns it jumped backwards, as if it was fidgeting. - 'Don't turn your watch with your back to the window in a north wind,' she repeated half-heartedly. - 'I mean... if I turn it around, it's bad? Leon snorted. - 'Or it will be very good,' he said, like someone who loves risk, but only in board games. Zosia pulled the slider, though the slider protested with a hoarse rasp. Then she set the watch on the table, with her back to them. They drew in the air and listened. The silence was so thick that they could hear the creak of wood in the walls and the flutter of a pigeon's wings somewhere behind the thatched roof. Suddenly, the ground floor of the library was cut by the sound of a bell. One, clear, spreading softly across the boards and books, like a wave on a pond. Zosia glanced at Leon. - 'It's twelve o'clock,' he said. - Someone must have hung up the pendulum, heh. The second bell joined the first, although it shouldn't have. Then a third. Zosia counted on her fingers, because counting in her head had suddenly become difficult. The fourth. The fifth. The sixth. On the eighth she felt the hair rising on the back of her neck. The ninth flashed through the glass of the vial so that the sand rose like snow for a moment. The tenth spilled across the ceiling. The eleventh trembled in the beams. The twelfth rocked the air. And then... another sounded. The thirteenth. It became a sound unlike any other. As if someone had touched an invisible string that passed through their chests. The watch vibrated and a tiny ripple trembled on its surface, though it was only metal after all. The ink on the note card lit up for a second with a dim, greenish glow and then went out. A patch of shadow blossomed from the floor, exactly where a ray of sunlight had fallen through the window grille. Not that ordinary - shadows are everywhere, after all. This one was more dense, as if it had its own weight. Instead of lying still, it was moving. Instead of spilling, it was gathering into a circle. Zosia crouched down, delighted and panicked at the same time, because both feelings can dwell in her at the same time. - Leon... - I see - he replied quietly. He did not blink. The shadow began to swirl. Slowly at first, like ice cream being stirred with a spoon. Then faster, until its centre became almost transparent. Something crackled on the planking of the floor and a thin fissure spread out radially, like a crack on glass. Zosia involuntarily drew her foot back. Something that looked like a step emerged from the darkness. Not wooden, not stone-as if made of light itself, which became hard for a moment. A second step appeared just below the first. Then a third, leading down into the depths of the shadows, where it smelled of cold air and sawdust. - 'Stairs,' Leon whispered, and his whisper rose and hovered, like dust in a ray of sunlight. The watch cycled louder, unnaturally loud for its size. The seconds hand began to move back smoothly, without stopping. The sand in the vial slowly shifted upwards, as if gravity had reversed just for a moment. Susan felt a chill on the wrists of her hands and the back of her neck, as if someone had just opened an ice-cold fridge. - This is not normal,' said the sensible part of her head. - 'Or maybe that's what normal looks like that we don't know,' replied the other part, the part that told Zosia to put her hand in the world's pocket and see what was in it. A quiet sound came from below, from where the darkness had thickened to the colour of old ink. First like a drop of water in a well. Then like a step. A single tap of a foot against an invisible step. The echo climbed the stairs, touched their ankles and rolled down the boards. - Did you hear it? - Zosia squeezed Leon's shoulder. - 'There's someone up there. The hair, gathered in a braid, moved down her neck as if a draught had touched it. Tiny sparks twinkled between the steps, like skylights in a jar. For a fraction of a second, Susan was sure that something more than their faces-lines she could not yet name, maybe a map, maybe writing-was reflected on the shiny surface of the watch. She squinted her eyes. Another step. Clearer this time, closer, as if someone - or something that could walk on tiptoe - was climbing unhurriedly. It didn't sound like the heavy boots of an adult or the stomping of a child. More like the shifting of a carpet of breath. - Sophie - a whisper sounded from below, soft and cool. Her name, spoken as if someone had already known it for a long time. The watch blinked with a single flash. The stairs vibrated, as if waiting for someone to set their foot on them. Zosia looked at Leon. Leon looked at Zosia. And an echoing whisper hovered between them like a question to which they still had no answer.