Paranormal investigator Zak Bagans documents the most authenticated case of possession in American history.

Zack Bagans investigates a home he purchased, sight unseen, after learning of its demonic history. This house became known as the demon house. Over the course of filming his longest and most challenging investigation ever, which also left him permanently scarred, Zack discovers some lost footage that wasn't included in the original demon house documentary. For the first time he has decided to release these terrifying events, that include additional night vision investigations of the house.