On the morning the town clock hiccuped, all of Windmarsh held its breath. Juni Chen and Rafael Morales were in the harbor square with paper cones of salt-dark cherries, watching the gulls wheel over the fishing boats. Wind blew the tang of seaweed and tar across the cobbles, and every shop door stood propped open to the sun. The clock in the old stone tower had just chimed eleven, bright as a handful of coins tossed into the air. It should have settled into its usual steady tick, a heartbeat you stopped noticing until it faltered. When it faltered. Tick-tick-ti- The sound caught and stuttered. The minute hand trembled, stopping halfway between the marks, as if it had changed its mind about moving forward. "Did it just... trip?" Raf asked, eyes narrowing behind his smudged glasses. Raf loved anything with gears and screws. He wore a backpack full of tools the way other kids wore sweatshirts. Juni squinted up. She didn't need glasses, but she loved patterns-the way maps told stories without words, the way fences lined up across fields, the way a town breathed in routines. A clock that hesitated? That was a wrinkle you could trace. "Maybe it's shy," she said. "Having a bad day." The hand quivered again. A gull laughed like it knew a joke. A burst of wind tumbled through the square and knocked something small and bright from a ragged banner overhead. It rattled across the cobbles and skittered to a stop against the toe of Juni's sneaker. It was a coin-or that's what she thought at first. Round and brass, as big as the rim of a jelly jar lid. But it wasn't a coin. It was a gear with twelve teeth and a tiny fern etched into its centre, its edges worn smooth by fingertips that weren't theirs. "Where did that fall from?" Juni asked. Raf crouched and turned the gear over in his palm. He whistled. "This is old. Look-the teeth are beveled. And the etching. That's not factory work." Juni leaned closer. The fern wasn't just a fern, not exactly. The fronds curled into numbers, not any numbers she knew, and the stem wound like a river across a map. The clock in the tower coughed another tick and stopped again, like a person learning to whistle. "The clock," Juni said. "Mrs. Lark is going to be furious." Imogen Lark was Windmarsh's clockmaker and everybody's aunt whether they wanted one or not. She kept a tiny shop on Mackerel Street under a blue awning, its windows crowded with tiny brass suns and moons. Raf looked from the gear to the tower and back. There was a light in his eyes that Juni recognised. He had that light the time he figured out how to make a broken toy car climb the banister. "We should take it to her," he said. "Now." They ran, cherries forgotten. Windmarsh slid by in a wash of green shutters and laundry lines. A cat blinked like a slow metronome in a doorway. A painted sign creaked. The awning on Mackerel Street lifted and slapped like a flag as they ducked inside the clockmaker's shop. It smelled like the inside of a music box-copper and lemon oil and faint sweetness-stacked from floor to ceiling with ticking. Not just one tick, but a hundred different ticks, some crisp like footsteps, some soft like rain on umbrellas. Clocks in the shapes of ships and swallows and teapots watched them with faces of bone-white porcelain. "Mrs. Lark?" Juni called. No answer came, but a little bell on the counter wagged back and forth of its own accord, chiming. A note lay under it in slanted ink: Back at the tower. If the bell sings, bring your feet. Raf held up the gear and grinned. "We've got the bell singing." The tower crouched at the north end of the square, older than the docks and older than the town's stories. The door at its base was oak with black iron hinges, always locked unless Mrs. Lark was inside, tuning wind and time. Today, the door stood open. Air moved out of the tower as if the building were breathing, cool and dry as old stone. Inside, a narrow spiral staircase climbed up into dimness. Juni swallowed. She wasn't afraid of heights. She was a little bit afraid of small spaces and staircases you couldn't see the top of. But the gear was warm in her pocket, pulsing a little, and the note had said bring your feet. They climbed, counting steps. Step thirty. Step sixty. Murmurs of sound grew around them-the tick of the town clock braided with other sounds, soft and low, like a hum you could feel in your ribs. When they reached the clock room, light spilled through the broad white face, the numbers reversed and watery. They stood behind the enormous hands, close enough to touch them, and tried not to. Mrs. Lark waited with her sleeves rolled up and her silver hair wound into a wick on top of her head, a pencil stuck through it like a flagpole. She was tall and wiry with grease on her fingers and spectacles perched on the end of her nose. "There you are," she said, as if she'd been expecting the exact sound of Juni's and Raf's shoes on the stone. She didn't turn around. She tapped the pendulum with one knuckle, listening. "Feel that?" Juni felt it. The air was alive. The pendulum swung steady but the room hummed in between ticks, a sound that made the hair on her forearms lift. "Is the clock broken?" Raf asked, breathless. "It stalled." Mrs. Lark's mouth tilted into a smile. "Not broken. Stubborn." She glanced over her shoulder. "What have we here?" Juni took the gear from her pocket. It lay warm and heavy in her hand. When Mrs. Lark saw it, the pencil in her hair shifted, and she reached for it without wiping her hands. "I wondered where this one had rolled." Her voice went soft and careful without losing any of its spark. "Fernwake. Haven't seen you in a summer." "Fernwake?" Juni echoed. Mrs. Lark turned the gear so the etched fern caught the light. It lit like a tiny brass river. "Each is named for what they remember," she said, and then, brisker, "Good work finding it. You two have feet that go where they need to." Raf looked like he might float. "What does it do?" Mrs. Lark tapped the side of her nose. "Helps with roofs. Helps with doors. Helps when things want to open and also don't." She crossed to a section of the stone wall where the mortar lines didn't quite line up. If you didn't look for it, you wouldn't have noticed-one rectangle where the stones were half a shade darker than their neighbours, as if a shadow had tried on the wrong coat. Mrs. Lark slid her ring along a crack, then pressed her thumb into a shallow circle in the stone. Something inside clunked like a well-tuned drum. The rectangle of stones sighed inward, not swinging like a door but yielding, as if the wall remembered being water. Behind it was not a room. It was a panel, all brass and glass, set with dials. The dials had symbols instead of numbers-little waves and leaf furls and curling winds. In the centre was an empty circle with twelve teeth. A place for a gear. Raf made a small sound that might have been a whisper and might have been a squeak. "Are we helping you fix the clock," he asked carefully, "or... something else?" Mrs. Lark didn't answer at once. Her eyes were bright, and the light from the clock face turned them the colour of old glass. "Windmarsh is a town that wears a coat of days," she said. "Underneath, there are other coats. Roads that don't show up on maps unless you're carrying the right kind of pencil. Doors that are stubborn until you ask the right way." Juni's heart beat in the same rhythm as the pendulum now. She glanced at Raf. He was not blinking. "Would you like to see?" Mrs. Lark asked. Juni didn't know if she answered out loud. She nodded. Raf nodded so hard his glasses slipped. Mrs. Lark set the fern-etched gear into the empty circle. It clicked into place as if it had been waiting for nothing else. She turned it once, twice. The hum in the room deepened. The panel's glass fogged, then cleared. The dials spun, then steadied with their pointers on a symbol that looked like the curl of a wave biting the moon. The clock ticked-and then didn't. There was a space between ticks wide enough to walk through. The air in front of the panel turned thick and bright, the way air looks over a road in summer heat, shimmering, almost liquid. Juni could smell something that wasn't the clock shop smell-wet leaves, cold stone after rain, smoke from a wood fire burned a long time ago. One by one, the numbers on the clock face overhead blurred and doubled. The bell rope stirred without anyone touching it. Low in the tower, something began to count, not with chimes but with a sound like a spoon tapping the rim of a glass. "Listen," Mrs. Lark said softly. "She's choosing." "She?" Raf whispered. "Time," Mrs. Lark said, like that answered everything and nothing. The shimmer wrinkled. Beyond it, a shape took shape-a slope of pale stones, a narrow bridge arched across a ravine, trees like hands reaching up, bare though it was summer here. Shadows moved along the bridge, quick and small and not quite like any shape Juni knew. "What's on the other side?" she asked. Her voice shook and then calmed itself, the way voices do when they know they're about to be told a story. "Depends when you ask," Mrs. Lark said. "And how polite you are. And whether you keep your promises." She turned the gear a hair more. The glow deepened to a colour Juni didn't know the name for. The panel thrummed. The bell in the tower began to chime. One. Two. Three. Juni's skin lifted with every strike. Four. Five. Six. She thought of rafters and tide charts and the way her mother folded dumplings into perfect little boats. Seven. Eight. Nine. Raf's fingers found hers and squeezed. Ten. Eleven. The twelfth chime hung and then went quiet without falling. In the hush, the panel made a sound like rain. The hand of the big clock jerked forward-no-forward and back, caught between minutes. And then the bell struck again. Thirteen. Juni's breath stopped. Raf said, "That's not-" but didn't finish. Mrs. Lark's mouth quirked, not quite a smile and not quite not. The shimmer pulled itself taut. The bridge beyond sharpened. A bright strand of something like silk seemed to string itself from the centre of the panel out across the room to the bell rope and back again, tying a knot around the moment. A chill slid down Juni's back and landed somewhere behind her heart. "Before we go any further," Mrs. Lark said in a voice that was still gentle but left no room to hide, "every door wants a promise. Can you keep one?" Juni didn't look at Raf. She didn't need to. She could feel the answer in the way his hand squeezed hers again. "Yes," she said. "Yes," he said, so quickly their voices almost braided. Mrs. Lark nodded once. "All right, then." She set her palm on the panel beside the fern gear. "We ask politely." She took a breath and spoke to the shimmering air. "Old road. We knock with our fern-wakes and wish to put our feet where they will be careful. Open for us, and we will close you after, tidy as a book put back on its shelf." The ripple bowed inward. Wind-wind from the other side-breathed into the clock room. It smelled like a thousand stories exhaling at once. The shape moving on the bridge paused, turned, and began to come toward them. Raf's fingers went colder in Juni's grip. "I don't think that's a person," he whispered. It wasn't. It was something quick and delicate, with more elbows than Juni had expected and a coat of all colours, flickering like oil and sunlight. It stepped closer with a click like two teacups tapping. It raised a narrow head. It looked right at them through the ripple. The bell rope trembled. The thing lifted its hand-paw-something-and tapped the air on its side of the opening three times. Tap. Tap. Tap. The rope twitched in answer. "Polite," Mrs. Lark murmured. "She's being polite. She's asking if we know our knock." Juni had never felt so steady and so ready and so shaky all at the same time. She swallowed. She opened her mouth to ask what their knock should be. And then the fern-etched gear under Mrs. Lark's hand began to turn by itself.