Every year the ocean takes a little more of Harbor—until it comes for the people. When a corpse washes into a living room on the last livable street, paramedic Wren Keene knows it isn't a storm surge. The tides aren't obeying the moon. Mail slots clack with letters no one sent. Bathtubs fill from the sea. And in the fog, a man with a ring of keys walks the routes like a ferryman taking attendance. With a perigean storm closing in, Wren pulls together an unlikely crew: Lina , a teenage field recorder who hears patterns in the hum; Jonah , a stubborn waterman with a bad knee; Mrs. Dorrit , keeper of the town's minutes and its dead letters; Dr. Corin Vale , whose "smart" drainage model may have taught the water to hunt; and Eli , Wren's father, whose lucid hours arrive like low tide. Their only chance is to unteach the town—strip the numbers, misfile the names, and raise a drowned ship's bell that can make the cut forget its appetite. But the ledger under Harbor keeps three columns—paper, code, and mouth—and it wants a final entry. As the highest tide of the year lifts, Wren must decide what to surrender: her deed, her name, or someone she can't afford to lose. A coastal gothic thriller about routes, debts, and a town that refuses to be counted.