This movie is the newest film by Saw creators James Wan and Leigh Whannell. It begins when a couple, Josh and Renai, moves into a new home with their three small children, and they immediately begin to realize that something is not quite right with the place. After several strange occurrences, their young son, Dalton, is lead into the attic by unseen forces. He falls off of a broken ladder, and when his parents answer his cries, they find him shaken but seemingly unharmed. The next morning, they become aware of the horrible fact that their son is in a coma.
Several months later, with Dalton still in a coma and no answer as to why, the mysterious instances began to escalate. Renai begins to see strange figures throughout the house, and her other son begins to insist that Dalton is walking around the house at night. One day, when she was changing Dalton's bed, she finds a bloody hand print on the sheets. That night, Josh comes home to find Renai sitting on the front porch crying. She tells him that she wants to move because she thinks the house is haunted, and when he starts to protest, she shows him the bloody sheet. After that, he agrees to find them a new home.
When they finally find a place, Renai seems to think that everything is okay. That is, until she sees a little boy who looks like Dalton dancing to "Tiptoe Through the Tulips" in her living room. She chases him through the house only to find her son still deep in a coma in his room. Beyond the breaking point, she calls Josh's mother for help. When she arrives, Renai tells her all that has happened, and you get the feeling that Josh's mother knows more than she is letting on when she says that she knows someone who can help.
Enter the psychic, with her two nerdy ghost hunting assistants, one of which is played by none other than Leigh Whannell, our resident writer. After a very short investigation using some toys-turned-ghost-seeking-equipment, the psychic proceeds to tell the family that the reason why their son is in a coma is because he is adept in the art of astral projection. She claims that his spirit is being held in a realm called The Further by the undead who is looking to take over his body. There is also a demon who is looking to take the young boy as his own. The group begins a strange ritual (that oddly includes a gas mask) that is supposed to draw Dalton back, but things go awry when the demon inhabits his lifeless body and creates havoc among them.
Afterwards, the psychic reveals that there is only one other way to get Dalton back, and we learn that the boy inherited his astral powers from his own father. Josh couldn't remember what had happened when he was a little boy because the psychic and his mother had helped him forget all memories of astral travelling and the old hag spirit who had tried to take his body. The group finally convinces Josh to go into The Further to retrieve his son, and after several run-ins with clown-faced ghosts and the puppet-wielding demon, Dalton is returned safe and sound to his body.
When everything seems like it's okay, the psychic senses that something is not quite right with Josh, and she snaps a picture of him before he could stop her. It is revealed through the picture that the old hag has taken full possession of his body, and the psychic is killed before she can warn the family.