Lana’s life unravels after the traumatic birth of her third child, when she is confronted by a ghost that only she can see―one who looks just like her and claims to come from a parallel reality. As the apparition, Allie, grows increasingly unstable, Lana is forced into a desperate battle for her mind, body, and family. As Allie’s sinister intentions come to light, Lana realizes this haunting is deeply tied to her unresolved traumas―and that Allie intends to replace her for good.