David finally figures out that Charlie is himself. 'Charlie' is David's murderous and psychotic alter-ego or other personality having emerged after he caught his wife cheating on him. Under the personality of 'Charlie', David later murdered his unfaithful wife by suffocating her, then placed her body in the bathtub, and slit her wrists in order to make it look like suicide. The minute David learns the truth, 'Charlie' emerges and fully takes over his mind. It is clear from this point onward that David no longer exists. When Sheriff Hafferty (Dylan Baker) arrives, having been called by the neighbors due to the disturbance in the yard, Charlie kills him and hauls the body into the basement, while Emily watches. He then begins to count down as for playing hide-and-seek, and Emily runs off to hide, just as Katherine arrives. Charlie pushes Katherine down the basement stairs where she sees Hafferty's body. Then Charlie goes after Emily with a butcher knife. Emily locks herself in her bedroom, climbs out a window, and runs to hide in the cave. Katherine, now armed with Hafferty's revolver, hears Charlie calling for Emily and follows his voice to the cave. Charlie and Katherine struggle, until Emily asks Charlie not to hurt her because Katherine is her friend. When Charlie turns on Emily, Katherine fires two shots into him, killing him for good. In the final scene, days or even weeks later, Emily has returned to New York. She is sitting at the dining table drawing a picture of herself and Katherine. Katherine tells her that they have to leave, so Emily finishes her drawing, puts on her backpack, and they walk out the door. The camera pans back to the drawing, and it can be seen that Emily has added an extra head to her own body.