Beneath the freight lanes and oil tankers, below the drag of anchors and the long, groaning shadows of cargo ships, the sea was never still. Far below the human world, cities adapted to every ocean climate—sprawling kelp metropolises in cold currents, coral citadels in tropical reefs, trench-set enclaves carved into volcanic stone. Thousands of kinds of merfolk moved through them. Towers grew like living reefs, pathways glowed with cultivated bioluminescent algae in soft blues and greens, and entire currents were harnessed and redirected into transit streams that carried citizens from district to district.

Most merfolk often lived in shoals—tight-knit collectives of mixed subspecies who swam, worked, and endured together. They were family, even if they didn't share the same blood.

Most followed that current. One did not.

Simon had never taken to shoals. Dependence had been taught out of him early until solitude felt safer than solidarity. So he kept to the shadowed shallows of freshwater. His dull, spotted, light green scales blended easily with duckweed and rivergrass, rendering him nearly invisible when he stilled. He had been shaped for the hunt—lean, quick, all coiled acceleration and sudden violence. An ambush predator by design, he knew how to wait without fidgeting, how to move without stirring sediment, how to strike without warning. Survival, for him, was not communal. It was precise.

And he worked alone.