When Lisa’s father is killed in a hit and run, we discover that he has a secret daughter from his first marriage. Her name is Marie and she is a convicted murderer, out on early release from prison, and driven by a single purpose–revenge. Living under a secret identity as Bethany, Marie has connived her way to living and working close to Lisa, lurking and planning her revenge as payment for the life she feels cheated out of–a life she feels their father unfairly gave to Lisa. Marie has set a deadly trap for Lisa to take back what she is owed, leaving Lisa, her mother and their friends to fight for their lives against the murderous sister she never knew.

À la recherche de l'âme sœur, Lisa fait croire à sa mère qu'elle est en couple avec un certain « Monsieur Merveilleux ». Cette prétendue relation remonte jusqu'au principal intéressé, Michael. Ce dernier retrouve Lisa et tous deux se rapprochent de plus en plus. Cependant, lorsqu'une de ses amies meurt, Lisa commence à douter des véritables intentions de Michael.