Evie (Nathalie Emmanuel), whose mother died and was unaware she had any other relatives, takes a DNA test and finds out she has a cousin she didn't know about. When her new family invites her to a lavish English country wedding, she finds herself drawn to the wedding's aristocratic host. It's not long before she finds herself in a nightmare of survival as she learns the terrible truths of her family's background and the frightening reasons behind their wicked generosity.