Fifty years after the allied air assault on Truk sank scores of Japanese ships, the islands face a new danger. Agent Paul Gerhart and his team are assigned to investigate the threat, but are coerced into including a reluctant, high-strung marine ecologist, Keira Hall. She's intelligent, attractive, and temperamental. Diving the precarious World War II wrecks, the team encounters deadly resistance from within, and face more peril from a ruthless and powerful enemy.