An eighty-meter rig support ship mysteriously disappears in the Caribbean with all hands, and an eccentric shipping financier knows the truth. Jayson Wilraven of the Marcene, a legend in the salvage community, is hired to lead the confidential job, only to find out the charterer wants the team to make sure the ship is never found.

Two thousand miles away, along the California coast, Jon Andreden starts underwater trials for Knowledgenix's next generation autonomous submersible, and is quickly pulled into an underworld of secret naval projects, killers who strike from international waters, people who live in the sea—the seaborn, and the first rumbling of a war of monstrous adversaries over control of the oceans and the future of human civilization.