After breaking up with her boyfriend at university, Alex attends a house party in her hometown with her childhood best friend. After meeting a new guy she agrees to return to his for a one night stand but he doesn't turn out to be who he seemed.

A woman Diane, has an affair while her husband is away with a younger woman, Jane. But as time passes the identities of the women come into question and revelations as to the nature of their relationships comes to the surface. All while strange occurrences happen around them, seemingly linked to mirrors around the house and a strange light that appears during the night.