Terror is evolving—as a new, unknown species of carnivorous marine life lays waste to an idyllic New York coastal town.

Marine biologist Katie DiNardo and ichthyologist Nick Tanner know about Mount Misery. For decades, out of this stretch of land on Long Island Sound, has grown the stuff of nightmares, legends, and grim folk tales. It's all been speculation and rumor, corruptions of the imagination—until now. Something has arrived in the neighborhood, and this time the locals have actual evidence of something nasty. One by one they're being terrorized. And one by one, they're being by killed by creatures with a taste for human flesh.

Kate and Nick have seen what this mysterious species is capable of. But to study it, to learn of its origins, and to determine how to stop it, they'll have go beneath the surface of the brackish coastal waters. What they find in the dark depths is beyond anything they feared or imagined—and even they may be helpless against the mounting and insatiable horror.