An alien spaceship lands in the English countryside and the werewolf-like creature assumes the identity of a young man he kills. Then, he finds his way to the house of a young woman and her house keeper, who are in a tentative lesbian relationship. But the young girl is also interested in men, much to her jealous lover's dismay. She'll do anything to keep her girl, even if that means killing this new mysterious man in their lives. She's a bit surprised when she finds out he's not exactly human.
PREY (also known as ALIEN PREY) has an unsettling quality of dread about it and the ending is something out of a classic Twilight Zone episode.