In the summer of 2003, twelve-year-old John Drenner Jr. finds an old abandoned shack in the woods surrounding Odenton, Maryland behind his grandmother's home. During his investigation of the shack, he came upon a book that detailed dark, satanic rituals, eventually learning the area was used by devil worshipers to perform their rituals. One night, his sister Cheryl hears him chanting in an unfamiliar language one night and when she stops him, his nose starts bleeding. Once the children go back home to nearby Pasadena, John becomes terrorized by a demonic entity every night who is hellbent on tormenting him, the demon refers to itself as "Legion", telling him that it won't stop until he is dead. The demon attacks continue on for the next few years. By the age of nineteen, John becomes use to the attacks not knowing who to go to for assistance with his tormentor. He goes as far as making suicide attempts to get out of it. Eventually, the demon begins to attack his girlfriend Mary with whom he had moved in with, hinting that it will kill her. John seeks help from a religious official who performs a deliverance on the young man, ridding him of the demonic attachment however he feels, one day, that the demon may return, seeking revenge.