Tidemark

Synopsis

Three centuries after the Great Surge — a catastrophic chain of floods, storms, and ecological collapse triggered by centuries of human overconsumption — the remnants of civilization cling to elevated megastructures called Spires, islands of concrete and salvage rising above a world swallowed by water and mutation. Below the Spire-cities, in the drowned sprawl known as the Shallows, life has adapted in extraordinary and terrifying ways. Crocodilians walk upright on muscular hind legs. Swarms of bioluminescent jellyfish coordinate like hive minds. Vast, blind leviathans patrol the deeper channels where old cities sleep beneath the silt. To keep the Spire populations safe, a guild of bioengineered specialists called Tidemarkers are deployed into the Shallows — surgically altered humans dosed with engineered enzymes and neural grafts that grant them enhanced perception, toxin resistance, and accelerated healing. Calder, a seasoned Tidemarker operating alone out of a rusting patrol skiff, has spent decades culling creatures deemed threats to Spire settlements. He is pragmatic, scarred, and deliberately emotionally detached — a professional killer of things that were never truly evil. When a contract leads him to a flooded delta community sheltering a young girl named Sable, a rare genetic anomaly who can instinctively interface with mutated wildlife without biotech, Calder becomes her reluctant guardian. As corporate Spire factions and a zealous purification cult both hunt Sable for opposing reasons, Calder's assignments grow darker and his certainty erodes. The creatures he kills to survive are simply life finding a way. The humans issuing his contracts are engineering extinction for profit. The real question Tidemark asks is ancient and unresolved: who gave anyone the right to decide what deserves to live?