David Hope, a charter captain in the British Virgin Islands, is a man severely shaken by personal loss and looking for nothing more than one last client to round out the season. At first it seems Sally Moffitt is his salvation. Beautiful and reckless, a filmmaker specializing in the mysteries of the deep, she meets David in a Tortola bar. Soon they are headed into the North Atlantic aboard Hope's catamaran Oona with a cache of “liberated” film equipment.
They encounter an an enormous dolphin of a species never seen, which presents the career opportunity of a lifetime for a nature documentarian. Pursuing the creature, which swims a relentless northeast course, they are hailed by the square rigged wind ship Star Of Alabama, a research vessel owned by the rich and powerful William Tree. Sally wants to keep her discovery for herself and David. But William Tree will not be put off, for he knows of a nightmare uncontained and all too real that is rising from the depths.
