When their friend Gabrielle is found covered in blood in front of their dead principal, with no recollection of what happened, Blythe, Tucker, and Tanya soon discover their lives are a lie as the walls built around their real memories come crashing down.

When Cayleigh, 17, loses her mother the excitement of her Senior year of high school is shattered. But when her deceased mother's hip distant cousin, Sienna, 40, moves in with Cayleigh and her father, 40, things start looking up. They don't realize Sienna is a psychopathic until it's too late as she will stop at nothing to make Prom a perfect night for her young cousin…including murder…