In all his years as a professional diver, Will Sturman has never encountered a killing machine more ferocious than the great white shark or as deadly as the piranha. Now, off the coast of California, something is rising from the deep - and multiplying. Voracious, unstoppable, and migrating north, an ungodly life form trailed by a gruesome wake of corpses. With the help of the brilliant and beautiful oceanographer Valerie Martell, Will finds himself in a race against time to stop the slaughter-by a predator capable of devastating the world's oceans.