Cancer Mercury felt the first crack split her vessel's hull an hour into the route. She kept moving through the dark water, watching the fissure spread along the curved wall. Her cargo of bottled memories rattled in their cases. She needed to find somewhere to land before the whole thing broke apart. The hull gave way with a sound like ice splitting. Glass bottles tumbled out into the black water, scattering in every direction. She watched them fall through the dark, each one carrying someone's grief or joy or regret. Some hit the sea floor and shattered. Others drifted intact, carried by currents she couldn't track. She let the vessel sink and swam down after the spill. A shipwreck rose from the darkness below, its frame curved like ribs. Purple lichen grew along its edges where coral had taken hold. The structure looked solid enough to shelter what remained of her cargo. She gathered the unbroken bottles one by one and carried them inside, stacking them in the empty hold. Each trip down felt heavier than the last. She dragged a massive anchor from the wreck's debris and set it outside the hull. The metal settled into the sand with a dull thud. This would be her resting point now. She had no route to finish, no delivery schedule to keep. The tears forming behind her eyes felt sharp. She pressed them back and went inside to count what she had left.

She woke to tracks in the sand. Pale blue light spread from the shipwreck's entrance across the seafloor, forming lines that stretched away into the darkness. The spilled memories had started to crystallize overnight, leaking from bottles she thought were sealed. Cancer Mercury followed the nearest trail. The crystallized memories had formed shapes as they hardened—a navigator's tool with brass rings and a compass rose, half-buried in silt. Further out, a helmet fused with tentacles rose from the sand like a monument to someone's fear of drowning. She recognized neither memory. They weren't hers to deliver anymore, but they were pointing straight back to where she'd hidden the rest of the cargo. Anyone could follow these trails now. She tried to cover the formations with sand, but more light leaked from the shipwreck behind her. A new trail was forming even as she worked. Where the brightest memories had settled, a turtle made of starlight and gold had crystallized into the seafloor, its shell catching every bit of ambient light and throwing it outward. The thing was beautiful. It made her angry. She couldn't hide what was already announcing itself. Cancer Mercury stopped covering the trails and walked back to the shipwreck. She pulled the remaining bottles from their shelter and arranged them outside in a wide circle around the wreck's entrance. If the memories were going to crystallize and mark her location anyway, she could at least control what they revealed. She opened each bottle carefully and poured the contents into the sand in deliberate patterns—paths that led nowhere, false trails that curved back on themselves. By the time the sun cycle shifted, anyone following the light would find only loops and dead ends. The real shelter, and what little cargo she had left intact, she moved deeper into the wreck where no light could reach.

By the next tidal shift, the false trails had done their work. The looping paths curved into dead ends across the seafloor, and Cancer Mercury sat at the mouth of the wreck watching them dim. She thought the crystal turtle would keep glowing steady, marking her from above like a lantern she couldn't put out. Instead, a hairline crack had opened along its shell. She heard it before she saw it—a small, dry tick, wrong for the water. She swam closer. The gold filigree along the turtle's back was splitting. Light bled from inside in thin ribbons, brighter than the memory light around it. Something was pressing outward against the shell. She could see the shape of it moving under the crystal, slow and deliberate, the way a hand tests a door. Cancer Mercury had built two armor plates from her own crystallized tears. She wore one on her chest, the other on her forearm. Neither was finished. She pressed her palm to the fracture and tried to hold the shell closed. The crystal was warm. That was the first wrong thing. Memory crystal ran cold. Whatever was inside was running its own heat. The shell broke under her hand. A cloud rose from the split—a metallic mist, threaded with flickering images she couldn't hold in focus. A face. A rope. A room she'd never seen. The mist gathered itself into a shape with two large, wet eyes and a trailing body, and it looked at her. Behind it, the crystal shell hollowed out and reformed into a ring, its rim carved with symbols, its center dark and shifting like a cut of open sky. A gate. Small, low to the seabed, but a gate. She understood then what her leaking cargo had been building toward. The memories weren't just marking her. They were assembling something. A door, and a courier to hold it open. The mist-thing drifted toward her forearm plate and touched it. The plate rang once, soft, and cracked straight down the middle. Cancer Mercury pulled her arm back. She had come here to become impenetrable. Instead her own armor had split at the first real test, and a piece of somebody else's grief was studying her like it knew her name. She reached into the wreck and dragged out the heaviest thing she had left—a blackened iron star, salvaged months ago, a dead courier's guild mark. She wedged the star into the mouth of the new gate. The symbols along the rim dimmed. The mist recoiled, thinned, and slid back through the ring before the light went out. The gate held shut. The turtle was gone. In its place sat a plain stone ring, quiet, closed, and hers to guard. Cancer Mercury sat down in front of it with her cracked plate in her lap. The shell she wanted would have to be built from something harder than tears. She had learned that much, and it had cost her half her armor to learn it.