Nyx came ashore where the black sand killed everything. She was a tan sphynx cat, part mermaid, and she had crossed the dark sea to grow flowers here. Her tail glittered as she dragged herself up the beach. She held a bundle of black foxgloves against her chest. The sand swallowed her boat's shadow. Within an hour, the foxgloves in her hands began to wilt. She knelt and pressed one bloom into the sand. It curled brown and died. She tried a second. Dead. The black grit burned her fingers with heat it had trapped all day. Nothing rooted here. Nothing lived. She understood then why the island lay empty. She had sailed for weeks to reach a graveyard. But Nyx had built gardens from nothing before. She would not sail back. She dug. She dug for days. Her claws split. The sand poured back into the hole each night. She built a stone ring to hold the walls and kept going. On the tenth day, her hand plunged into cold. Dark water pooled at the bottom of her well. She cupped it and tasted salt and rot. It would kill her flowers faster than the sand. So she built. She raised a greenhouse of black glass beside the well, shaped like a pyramid with a half-moon door. She rigged a pump to pull the water up. She strained it through cloth and charcoal, again and again, until the salt was gone and the rot was gone. Clean water dripped into a trough. She mixed it with ash and crushed shell and made a small bed of soil on the pyramid floor. Into that soil she pushed her last living foxglove. Then she waited. On the third morning, she saw it. The stem stood straight. A bud swelled at its tip. By nightfall the flower opened, black as the sand outside but glittering with fine gold flecks. A thin trail of gold dust drifted up from its throat like smoke. It was more beautiful than anything she had grown in her life. She had beaten the black sands. Nyx laughed and cupped the bloom. Gold dust settled on her wet fingers. She lifted them to her nose and sniffed. Her throat closed. Her vision swam. She stumbled back and caught herself on a pot of twisted black sticks by the door. The flower was poison. Its scent alone could drop her. She had grown a killer. When her breath returned, she stared at the bloom through the glass. Her small well could feed one flower. But the water beneath the sand ran deep. If a spring lay under this whole island, she could turn the graveyard into gardens for miles. She wiped the gold from her hands and picked up her digging tools. The well was only the start. She had to find where the dark water began.

The well had fed one flower. Nyx wanted more. Before dawn she waded into the black tides past her greenhouse and dug her claws into the wet sand. She was hunting the place where the dark water ran deep, the spring that could green the whole island. The tide reached her waist. She worked the sand loose, cup after cup, and felt the pull of something colder underneath. Then the water rose against her. It climbed her chest without a wave to push it. A shape gathered in the black surface, tall and star-flecked, shaped like a woman with a pharaoh's crown. Its silhouette held tiny points of light, like sky poured into a body. It did not speak. It reached, and the tide reached with it, dragging Nyx toward the deep. She kicked. The sand she had loosened gave way beneath her. She went under. Water filled her ears. The spirit's hand closed on her tail. Cold burned through her scales. She understood then that this thing lived in the deep water she was chasing, and it would drown her before it let her take one drop. Nyx clawed at the seabed for anything solid. Her hand closed on a shard of gold half-buried in glittering silt, a fallen star fragment cold as the tide. She jammed the sharp point into the spirit's grip and twisted. The star-flecks in its arm scattered like sparks. The hand let go. She broke the surface, gasping. The spirit rose after her. She scrambled for the shore, but the black sand offered nothing to hold. Her fingers found the drape of dark kelp hanging where the tide had left it snagged on stone. She hauled on it, hand over hand, and dragged herself out of the water. On the sand she turned. The spirit hung at the tide line, unable to leave the water. It watched her with pale eyes. Then it sank without a sound and was gone. Nyx lay still until her breath came back. The lesson was plain. She could not dig the deep water alone. The thing beneath the tides would take her the moment she went in. But the shard in her fist still glittered, and near it, where her runoff from the greenhouse had seeped down to the shore, something had changed. A patch of dark grass grew in the black sand. Blades so deep green they read as near black, thick and living, watered by the clean spill from her pump. Her purified water had reached beyond the pyramid on its own. It had grown grass in ground that killed everything. Nyx pressed her palm to the turf. It held. The island could be greened after all. But the spring she needed lay under the spirit's water, and no shovel would win it. She needed to learn what the thing in the tides wanted. She would have to ask someone who spoke to spirits.

Nyx wrapped the star shard in wet kelp and left her greenhouse behind. She could not fight the spirit in the tides. She had to understand it first. She needed the map of the deep water and the truth of the thing that guarded it. Twin black pyramids rose ahead, their gold moons catching the dawn. A stargazer lived here who charted the black sea and the sky above it. Inside the glass wing, a sphynx mermaid bent over a telescope. Nephthys Starweaver did not look up. A star chart hung near her, black etched with gold rings and marks. Between the plants, a skeleton cat lay flat on the warm sand, tail curled. "I need to reach the deep spring," Nyx said. "I need to know where the water runs under the tides. You chart the sea. Do you have the tides?" Nephthys tapped the gold chart. "The pull, yes. Not the bottom." She traced a ring of marks. "The deep water sits here. Under the black sand shelf. The tide covers it twice a day." She looked at Nyx now. "You dug there already." "It nearly drowned me," Nyx said. "Something in the water. Star-flecked. Shaped like a woman with a crown." The skeleton cat lifted her head. Her jaw parted. A low hiss slid out. The air near the glass seemed to thin, as if the light dimmed before it reached her bones. Nephthys went still. "Rue only hisses at bad ones." "What is it?" Nyx asked. "You see spirits. Tell me what it wants." Rue rose on all four legs. Her yellow eyes fixed on the shard in Nyx's kelp. "It guards the spring," Rue said. "Not for hate. For grief." One idea, then she stopped. Nyx crouched to her level. "Grief for what?" "The drowned ones," Rue said. "It holds sailors under the black tide. Alive. It cannot let them go. So it lets no one in." She sniffed the kelp. "You carry its light. A piece of it fell." Nyx unwrapped the shard. The gold caught the lamp. Nephthys drew a sharp breath. "That is not sea gold," Nephthys said. "That fell from the sky." She held it against the chart. The mark on the shard matched a ring near the deep water. "The spirit sits where a star came down. The two are joined." Nyx understood then. The spirit was not simply a guard. It was tied to a fallen star, weighed down by the sailors it could not release. Force would never move it. But a fallen star was something she could return. "Where did this piece fall?" Nyx asked. Nephthys pointed to the ring on the chart, then to the tide line beyond the glass. "There. Where you nearly died." Nyx wrapped the shard again and stood. She had her map now. She had the spirit's wound. The spring was not won by digging but by giving the star back. Now she had to carry it into the water that had almost killed her.

Nyx left the pyramids with the star shard bound in wet kelp against her chest. The chart had shown her the ring where the star fell. Now she had to reach it. She swam along the shore until she found a tall black stone standing in the sand. An arrow pointed north. Below it, someone had carved a cave and a mermaid. This was the marker. The cave lay ahead, under the tide. She dove. Black water closed over her. Below, a mouth of glittering stone opened in the sea floor. Water rushed into it and out of it, pulling hard. Palm shapes of black rock leaned near the entrance. She kicked toward the dark opening. Then the deep tide caught her. The pull dragged her sideways, away from the cave. She fought it. Her tail slapped water that would not hold. The shard shifted in the kelp, and for a moment she nearly dropped it. She grabbed the wrapping with both hands and let the current take her, then twisted with it instead of against it. The tide slung her past a cluster of jagged black rocks. Sharp specks glittered along their edges. She caught one, held, and pulled herself into the cave mouth. Inside, the rushing water calmed. She surfaced in a still pool. Then a shape rose from the dark ahead. A dragon coiled at the far wall, black as the void, its body dusted with tiny stars. Blue eyes fixed on her. It filled the passage to the deeper chamber. Behind it, a faint light waited. Nyx did not move. She held the shard out on her open palms. "I am not here to dig," she said. "I brought back what fell." The dragon lowered its head. Its breath stirred the water. It did not strike. It watched the gold in her hands, then drew its long body aside, clearing the way. She swam past it into the inner chamber. The spirit waited there. A woman shaped from black sky, her hair drifting like smoke, stars scattered across her form. A crown sat on her head. Grief hung around her the way cold hangs in deep water. This was the thing that had almost drowned her. Nyx unwrapped the shard. "This is yours," she said. "You have carried too much. Take it back." The spirit reached out. Her dark hand closed over the gold. Light spread through her body, and her form settled, the sky in her going still. She bowed her head to Nyx once. Then the deep tide changed. Nyx felt it in the water, a pull no longer fighting her but drawing her down and inward, toward a passage behind the spirit. Fresh water, cold and clean, poured from it. The guardian had opened the way to the spring. But far below, in the drowned dark, Nyx heard the faint knocking of the trapped sailors, still alive, still held. The spirit had let her in. It had not yet let them go.

The spring poured clean and cold from the passage behind the spirit. Nyx cupped her hands and drank. Fresh water, no salt, no rot. This was what she had dug for through years of black sand. But the sailors' knocking still echoed below her, faint and steady. She could not free them. She could only carry their water up to the light. She followed the flow out of the glittering black cave. The spring ran with her, spilling over ledges of dark stone, pooling in stair-stepped basins between stark black palms. She marked the path in her mind. If she wanted this water to green the whole island, she had to move it. Water did not climb sand on its own. Nyx knew a well on the far shore. An old stone ring, deep and dry, its dark pool long gone still. If she could link the spring to that well, the flow would reach the sand near her greenhouse. She swam back for the glass pipes she had built for such a day. Straight tubes, sealed tight, the same ones she used to lift saltwater to her greenhouse. She fitted the first pipe to the spring's mouth. Water rushed in and swirled dark, threaded with green from the deep. She laid the next pipe, then the next, dragging them across the sand, digging channels to hold them. Her arms ached. Grit crusted her tail. The knocking would not leave her ears. She dug faster, as if speed could pay a debt she could not pay. Halfway across, her trench crossed old wreckage. Broken timbers, split planks, rusted fittings half-buried in black sand. A drowned ship, long forgotten. She stopped. These planks had carried men once. Maybe the same men who knocked below. She pulled the debris aside and kept laying pipe through the grave of it. At last the line reached the old well. Nyx sealed the final joint and opened the flow. For a moment nothing moved. Then dark, green-flecked water climbed the pipes, filled the ring, and rose in the deep pool. It caught the light in tiny glittering points. The spring had reached the surface, miles from where it hid. She knelt beside the well and watched. Around its base, where a little water had already seeped, thin blades pushed up through the black sand. Dark grass, near black, tipped with forest green. Living turf, growing where nothing should. Nyx pressed her palm flat to the new grass. It held. She had done it. The spring flowed free, and now it flowed where she wanted. The island could be greened. But the sailors were still down there. She had taken their water and left them in the dark. She stood, wiped the grit from her hands, and looked back toward the cave.

The grass around the old well still held when Nyx left it. She swam and walked the long way home, dragging one last coil of glass pipe. The spring flowed. The island could green. But the sailors' knocking followed her the whole way, faint and steady in her ears. She had taken their water and left them below. Her greenhouse rose from the black sand, a dark glass pyramid with a half-moon door. Inside, water threaded through her glass lines, deep green swirled with black glitter. Nyx set down her pipe and looked at the beds she had cleared for new plants. She meant to fill them today. She had carried seeds and cuttings back with her for weeks. She knelt at the far wall, where the glass framed the dark palms and dripping vines. She pressed a black aloe into fresh soil. Its thick leaves glinted with tiny points of light, like grit caught in water. She had grown it to close wounds. She patted the soil down and moved to the next bed. There she planted a flytrap, its dark mouths open and waiting. Then a row of near-black foxgloves, careful with her bare hands. One brush of their gold dust could stop a heart. She worked in silence and tried to think only of roots and soil. But the knocking would not leave. Every time she pressed a seed down, she heard it. She grew things to save the island. Below the spring, men were dying in the dark, and she had walked away with their water. The two truths sat side by side and would not fit. Nyx stopped. She looked at the black aloe, at its healing shimmer. She looked at the foxglove that killed. Both grew from the same spring water. The same water she now sent across the island. If that water could raise a plant that mended flesh, maybe it could do more than green sand. She stood and wiped her hands. The greenhouse was finished for today. The beds were full. She had done what she came home to do. But planting had not quieted her. It had done the opposite. Every root she set reminded her of the men she had not freed. She walked to the half-moon door and looked back at the spring's direction. She could not keep growing gardens on top of a grave. The water fed her plants and drowned those sailors at once. She would not choose one over the other any longer. Nyx sealed the door behind her. She had come home to plant, and she had. Now she knew the planting was not the end. Tomorrow she would return to the cave. Not to take more water. To find a way to let the sailors out.