After losing her mom in an accident, a teen and her father welcome a distant cousin named Sienna into their household. Hoping to claim the family as her own, the psychopathic Sienna hatches a devious plan to recreate the prom she never experienced.
After her brother is killed in self-defense by his ex (Madison) whom he'd kidnapped, Lisa decides to take revenge on Madison by using a trauma support group to become her friend.
