On a sweltering night deep in the bayou, Shelly, a mystical mermaid, witnesses a horrifying act. With a monstrous killer now hot on her trail, Shelly has no choice but to turn to Sheriff Tillman Angier, who's had his eye on the honey-haired beauty for a while. The feelings are mutual, but he's determined to solve the murders, and he knows Shelly's hiding something . . .