Married couple Bob and Susan Howard decide to see a marriage counselor named Judy Small, who appears trustworthy but harbors dark and conflicted impulses.

The story follows Joe, (Cage), a down-on-his-luck truck driver haunted by the memory of his deceased wife and child. He meets Julie (Potente), a spiritually gifted woman who enlists Joe in a desperate effort to find the lost soul of her comatose daughter, Billie (Mitchell). But the spirit of Joe's dead wife Mary proves stronger, possessing the young woman's body and determined to settle her unfinished business with the living.