Rain rattled the windows of Hart's Clockworks and turned the street outside into a glassy ribbon. Inside, clocks of every size filled the walls-pendulum clocks with patient swings, tiny travel clocks with brass feet, and a towering grandfather clock with a face like the moon. Their ticking blended into a soft, steady heartbeat beneath the roof. Maya Hart pressed her cheek to the cool glass of the front window and drew a smiley face in the fog with her fingertip. She was eleven and liked notebooks that snapped shut with a satisfying click, and pencils sharpened to perfect points. Her older brother, Theo, knelt on the worn rug near the counter with a screwdriver between his teeth and a pocket watch in his hands. Theo was twelve-and-a-half, which he said mattered very much, and he could take apart almost anything without losing a single screw. "Dad's going to be forever," Maya said, watching the blurry shape of their father and the delivery truck disappear into the rain. He had left to deliver a restored grandfather clock to the mayor's office. "We could finish our timeline project before he gets back." Theo looked up, dark hair flopping. "We could finish it. Or we could make it amazing." He tapped his notebook, where he had scribbled: Inventors of Gullhaven Harbor. "Amelia and Josh are doing a poster with glitter. We need something better than glitter." Maya thought of the school gym filled with tri-fold posters and bowls of candy. She wanted their project to be the one people actually read, the one that made their teacher, Mrs. Grant, widen her eyes. "Better than glitter is a high bar," she said, but she was already glancing towards the stairs that led up to the attic. The attic held boxes from the days when Great-Grandmother Eliza Hart ran the shop. If anyone had left something fascinating behind, it would be Eliza. They climbed the narrow staircase, each step a hush of old wood. The attic smelled like cedar and wool and the faint, dusty sweetness of dried flowers. Light sifted in through a round window, making rain stripes across the floor. Trunks were stacked like sleeping elephants. A row of hat boxes leaned against a coil of rope. A drawer labelled Odd Parts had a stubborn knob and a heap of tangled chains inside. "This place is like a museum exploded," Theo said happily. He pulled a sheet off a wooden crate and sneezed. "Bless me. Ooh-check this out." In the corner, under a faded quilt stitched with stars, they uncovered a narrow wooden chest with brass corners and an anchor carved on the lid. Someone had nailed a small metal plate to the front, and words were stamped into it in neat letters: FOR WHEN YOU ARE BRAVE ENOUGH. Maya looked at Theo. Theo looked at Maya. "On a scale from one to brave," Maya said, "where are we?" "Solid eight," Theo said, although his eyebrows were doing an excited dance. He slid the latch. The chest opened with a sigh, like it had been holding its breath for years. Inside, nestled in a fold of dark blue velvet, lay a thing that was not quite a watch and not quite a compass. Its case was warm brass, smooth with use. Around its edge ran a ring etched with months and tiny numbers, and under the glass a second hand quivered even though nothing ticked. A thin needle hovered above a little rose pointing to North, except the needle wasn't steady-it tugged toward a small engraving shaped like an hourglass. A leather strap, cracked and honey-brown, curled from its sides. On the back, someone had scratched delicately: To cross the sea that isn't water, set your course and keep to it. There was also a folded note, tied with a faded ribbon the colour of tea. Maya untied it with careful fingers and read aloud. "If you have found this, then clocks have already led you as they led me," she began. "Time is a sea. Do not forget that the tide runs both ways. The thirteenth chime marks the door. Do not change what you do not understand. Leave breadcrumbs-ink, chalk, a song-so you may return the way you came. -Eliza Hart." Maya swallowed. "The thirteenth chime?" Theo's eyes gleamed. "Clocks only go to twelve." "Exactly," Maya said, which did not make her feel better. She turned the device over in her hands. The brass was warm, as if it had been tucked in a pocket a moment earlier. On the side was a ridged crown like those on old watches, and a small copper button shaped like a droplet. The ring of months and numbers could be twisted, and as Maya tried it, the faintest vibration shivered through her fingers. "We could set it to last week," Theo said. "Just to see if it-if anything-" "If it what?" Maya asked. "Plops us into Monday? I didn't even finish my math on Monday." Theo laughed, but his voice was soft. "Or we could set it to something useful. The lighthouse. Remember what Mrs. Grant said? 'Gullhaven's first lighthouse lamp was lit August 12, 1903.' We could see it. We could take real notes. We could do better than glitter." Maya pictured the black-and-white photograph from their textbook-the lighthouse beam stretching like a paintbrush across the bay. The idea tugged at her the way the needle tugged toward the hourglass. "Just look," she said. "We only look." They bent over the device together, heads nearly touching. With a tiny click, Maya turned the outer ring until AUG lined up with 12. Theo adjusted the inner numbers, his thumb steady, until 1903 rested in a little window that had been empty a moment before. Neither of them breathed when the empty window was suddenly full. "Focus point?" Theo murmured, scanning the face. A barely visible line of letters appeared where there had been nothing: HART'S CLOCKWORKS, ATTIC. As if the device knew exactly where it was. "That's not creepy at all," Maya said, although the back of her neck prickled. Theo reached for the ridged crown. "Breadcrumbs," he said. He chalked a little spiral on the floorboards and wrote NOW with an arrow pointing to their feet. Maya, feeling very much like they were about to step onto ice, opened her notebook and wrote: AUG 12, 1903. Lighthouse lamp. Don't touch anything. Come back at thirteen. "Ready?" Theo asked. "No," Maya said truthfully. "Do it anyway." Theo smiled, took a breath, and wound the crown once. The nearly invisible second hand gave a delicate hop-backward. The attic's usual quilt of ticking unraveled into silence, and then, slowly, returned as every clock in the shop below began to tick in perfect unison, like a hundred hearts beating together. Dust motes hung in the air and then-Maya's breath hitched-drifted upward instead of down. The rain-soaked light slanting through the round window shifted colour, turning thicker, golden as syrup. A salt smell-sharp and clean-pushed away the cedar. From somewhere far off came the hollow cry of gulls, and beneath it, faint and steady, the sweep of waves against rock. "Do you feel that?" Theo whispered. It was as if the floor had remembered a different shape and was trying it on; not moving exactly, but settling into an old groove. Maya's fingers tightened around the brass. The copper droplet button gleamed. It seemed to want to be pressed. The words on Eliza's note curled through her head: The thirteenth chime marks the door. "On three," Theo said. "One." His eyes met hers. "Two." Maya nodded. "Three." She pressed the copper button. Every clock in Hart's Clockworks began to strike the hour. One, two, three-notes stacking like steps inside the walls. The grandfather clock boomed, and its deep voice bounced through the floorboards. The round window fogged over, then cleared to a view that didn't belong to a rainy afternoon: masts bobbing in the harbor where there shouldn't be any, a narrower street, a sky with a different kind of clouds. Between the boxes and trunks, the air pinched into a thin, bright seam. Twelve. The seam glittered like a line of light drawn through water. On the other side, something moved-a splash of a dark coat, the shape of a lantern, a flicker like the swing of a ship's bell. A draft slipped through, cool and sea-tanged, and it carried a voice so faint you could almost pretend you hadn't heard it. "Maya. Theo." They froze. Maya's hand found Theo's. The thirteenth chime gathered in the air, low and impossible, and the seam stretched open just a little wider.