Rising from the depths, a mind-bending monster unleashes a wave of terror across the American heartland. Kate Browning, a Kansas City EMT confronts her paralyzing fear of water when she traces the source of a deadly parasitic affliction to the Gulf of Mexico. Cooperating with a marine biologist, she travels to Florida in an effort to save the life of one very special patient, but the source of the epidemic happens to be the nest of a terrifying monster, one that last rose from the depths to annihilate the lost continent of Atlantis. Leviathan, destroyer, devoted lifemate and parent, the abomination is not going to take the extermination of its brood well.