Jessica Barrett, wife and mother of two young children, begins to show signs of demonic possession while pregnant with her third child. As she seeks help from her husband and doctor, a mysterious man approaches her and seems to have some answers.

Julia (Trish Everly, in her only film role), a young teacher for deaf children living in Savannah, Georgia. Julia has horrid memories of her childhood, which was scarred by her sadistic twin sister Mary (Allison Biggers). At the urging of her uncle, Father James, Julia visits Mary, suffering from a severe skin disease, in a mental institution. The meet does not go well, and Mary vows to make Julia “suffer as she had suffered”. As their mutual birthday approaches, several of Julia’s friends and neighbors begin to die gruesome deaths, some of which committed by a mysterious Rottweiler dog that has some sort of connection to Mary. But is Mary really the killer?

Several people disappear from and at the sea. Their bodies are found gnawed to the skeleton, even the marrow is missing. The scientists have no idea which animal could do such things. Dr. Turner begins to suspect that the company which builds a tunnel beneath the bay might have poisoned the environment and caused an octopus to mutate to giant dimensions…