After a fierce storm, a mysterious tadpole-like creature the size of a rhino washes up, apparently dead, on the shores of Seal Cove, Nova Scotia. The newly discovered animal is transferred to an empty pool, where marine biologist Michael Keating tries to determine what it is. Later that night, the creature emerges from its dormant stage, transforming into something monstrous. The residents of this isolated coastal town must rely on each other and their limited resources if they are to survive the raw October night and the hungry flesh-eating predator that has made Seal Cove its hunting ground.