The harbour clock in Wrenhaven struck thirteen at noon, and everyone pretended not to hear it. Gulls startled from the pier with a sudden white flurry, and the wind brought the wrong smell-rain, but also cold metal, like coins rinsed in salt. Aisha paused on the uneven cobbles, one boot toe on a chalk line she had drawn last summer. She counted under her breath. Twelve. Thir-no, that wasn't possible. Beside her, Milo tilted his head and frowned at the sky as if the sound might be hiding up there. "Did it...?" he began. "Thirteen," Aisha said, though her voice came out softer than she meant. The word felt like a pebble dropped into deep water. Aunt Noor glanced up from the brass gears she was turning in her workshop doorway. She had a pencil behind one ear and a smear of varnish on her knuckle. "Clocks do odd things when the weather's wrong," she murmured, almost to herself. Then she noticed the bundle under her arm and pressed it into Aisha's hands. "Take this while you're going. The tide clock at Storm Point seized up again. Since you begged to see the lighthouse, you can deliver the oil and the rag and-oh-this." She tapped the wrapped parcel. "Found it in a drawer that wasn't there last week. Belonged to Keeper Gray, I think. Be careful, and be back before the real storm starts." Milo's eyebrows climbed. "A drawer that wasn't there?" Aunt Noor only smiled as if that answered anything. "Mind the steps," she added, and went back to her tinkering. Storm Point Lighthouse rose from a scab of rock at the edge of the bay, its white paint chalky with salt and sun. The lantern room glass had been boarded for a year, since the last keeper took the ferry and didn't return. Kids in town whispered about a steady hum at night and a pale glow no one could find the source of. Adults said the hum was the sea talking to itself. They said the glow was nothing. Aisha had wanted to see it herself ever since. They followed the breakwater, waves sighing at their ankles. Milo carried the oil and the rag. Aisha carried the bundle. The cloth came loose with the tide wind, and she tightened it, but not before she saw a flicker of greenish shine. The parcel was heavier than it looked, and warm, as if it had been held a long time by someone else. "What is it?" Milo asked. "We'll open it there," Aisha said. She wasn't sure why saying the words made the harbour heart beat faster. They reached the black iron door at the base of the tower and found the chain strung across it like a stern eyebrow. There was a small wooden sign-Lighthouse Closed for Repairs-though the letters had faded so much they read more like a wish than a rule. "The boathouse," Milo said. "There's another way in." He'd spent last summer hauling rope for fishermen and knew the harbor as well as anyone. Around the lee side, down a wet set of steps slick with seaweed, there was indeed a lower door, green with moss and swollen with many storms. It stuck at first, then shuddered inward with a groan that sounded like old bad manners. Inside, the lighthouse smelled of salt, oil, and dust. Ropes hung like sleeping snakes. A single narrow window let in a thin coin of light. A ladder climbed up into the shadow of the tower, and somewhere above, something small skittered and then held its breath. They set the oil and rag on a workbench by a wall of pegs. Aishas fingers went to the bundle and unwrapped it. The cloth fell back on a brass circle the size of her palm-part compass, part watch, part something that didn't quite want a name. The glass was not quite clear; it had a wavering like heat above a road. Little flakes of dried sea salt were caught under the rim. Around the edge, letters had been etched, not with A, B, C, but with symbols like tiny waves, triangles, and arrows. The needle did not point north. It shivered, thought about it, then swung to the stone floor, as if it had heard something below them calling. Milo whistled softly. "That's not normal." "Nothing about thirteen at noon is normal," Aisha said. She held the compass flat, and the needle turned toward the inner curve of the lighthouse wall. When she took a step, it nudged in her palm like a guiding elbow. They climbed the ladder carefully, the rungs black with old oil. The first landing was a ring of light through a tattered curtain. On one wall hung a chalkboard with faded dates and tides. On another, a map of the coast with brass pins marking reefs and channels. In the corner stood a narrow cot with a neat folded blanket. A ship's log lay open on a small table, the ink pale and gray. Aisha brushed the dust from the page. 24 September. Bell struck thirteen. Lantern bright without flame. If this is a joke, I don't like it. -E.G. The pencil mark at the end had dug into the paper, as if the hand had pressed too hard. "Keeper Gray," Aisha whispered, and the room felt as if it had been waiting for someone to say the name. The compass twitched so sharply that she nearly dropped it. The needle was pointing, not to the sea, not to the map, but to a thin seam in the floor beside the map case. If she hadn't been looking at exactly the right angle, she would never have seen it, a hairline gap between two pale boards. "Help me," she said. They slid the map case-carefully, because it creaked like something that wanted to be left in peace-and the floorboard at its base gave a tiny click. Milo ran his finger along the seam. There was no handle. There was, however, a dull circle the size of the compass, set flush with the wood. Aisha pressed the compass against it before she could second-guess herself. The brass rim met the circle with the slightest kiss of metal on metal, and something beneath the floor sighed. The board rose a finger's width, then more. A square of shadow opened, and a cool breath of air came from below, smelling of damp stone and the ghost of a storm. A cast-iron spiral descended into the dark like a coiled rope. "We should text Aunt Noor," Milo said, patting his pocket. There was no service bar, not even one that flickered and lied. He tried anyway. The message didn't go. "We go two flights, we look, we come back," he said, as if making a promise out loud could make it true. Aisha nodded. She pulled a carpenter's pencil from the workbench, drew an arrow on the floorboard toward the open hatch, and wrote: A&M DOWN. BACK SOON. It felt bossy to write to the empty room, but also necessary. She tucked the compass in her jacket, where it beat faintly against her rib like a second heart. They went down. The spiral stair groaned but held. The stone around them was cold. The walls had shallow carvings: fish spines, wave lines, little suns with too many points. At the first landing, they found a room that did not seem to know it was below ground at all. A narrow window ran along one wall, a thick ribbon of glass that looked out-impossibly-into greenish water. Spadefish glided past, silver mouths opening and closing like surprised old men. "We're under the bay," Milo breathed. The compass needle was pointing straight at the glass, then down again, impatient. The second chamber was full of charts and odd instruments. There was a brass frame with strings stretched tightly across it like a harp, but the strings moved with no fingers. They thrummed a low note that Aisha felt in her chest more than she heard with her ears. A message box sat on the table with a paper roll wound through it. Words had been typed in wonky letters, as if by a machine that got seasick: HOLD THE LIGHT STEADY. HOLD THE- and then the line ran off the page as if someone had walked away in the middle of it. Milo found a shelf of glass tubes with corks, each with a date written in neat figures. In the bottom of the room, a narrow channel cut through the floor like a little canal. Water moved there. Not much, and not with wave-slap, but with a steady purpose, as if obeying a clock. "Who built this?" Milo asked, not expecting an answer. The compass tugged, and Aisha tugged back. "All right," she said to nobody and to it. "We're going." They followed a corridor that sloped deeper, the ceiling low enough to make their shoulders want to hunch. The hum grew-a sound like a whale talking and a violin string in a storm. The air felt charged, as if they had walked into the breath before lightning. At the end of the corridor was a round door set into the rock. It had no knob. It had concentric rings etched with those same wave and triangle symbols, and in the centre, a shallow cradle the size and shape of the compass. Aisha looked at Milo. Milo looked at the door. "We said two flights," he reminded her, because that was what you did when a part of you had already leaned forward. "This is the second flight," Aisha said, which was not exactly true but felt like it wanted to be. Her hand went to her jacket. The compass warmed as if it had been waiting for the air in this place all along. She set it into the cradle. It settled like a coin in aishing well. For a breath, nothing happened. Then the rings began to turn with the soft, satisfied sound of gears that have been oiled for a hundred years. Lines along the ceiling woke up, faint and blue, like veins. The water in the narrow channel stilled, as if listening. Somewhere above them, the harbour clock hesitated, then struck once. The sound traveled down the stone like a thought and reached the door in the same moment the last ring clicked into place. Air whooshed from the seam. The door shivered. A thread of cold, salt rain-smell slid out and curled around Aisha's ankles. The blue lines flared brighter. "Do you hear that?" Milo whispered. They both did. Beyond the opening edge, not sea and not wind, something moved. It wasn't loud. It was the slow, heavy shift of weight you feel more than you hear, the sense that a very old thing has turned its head. The door began to swing inward. A shape leaned into the light. And from the dark beyond the threshold came a sound like an answer.