The story is about Joel, a man struggling to keep it together so that he can keep his son Mason with him.He works as a mechanic, sees a therapist on a regular basis, and has a babysitter to take care of his son when he has to go work.With what little he has, he has managed to keep stable. But he does see visions of demons that he believes to be because of his schizophrenia.Joel tries to make his life work and when we see him blow up in anger, his frustrations are palpable.Then one day, the babysitter announces that she's leaving for college. As good as her intentions are for helping out Joel, she barely gives him enough notice to find another babysitter.Seriously, she knew what kind of trouble she was getting Joel into considering he still didn't have a stable enough job. So she leaves, but she notices something weird about the way Mason behaves.Soon, Joel discovers that his son is behaving in a weird manner and things around the house move on their own.Meanwhile, the babysitter enlists the help of a priest who was disgraced by the media for killing children during his exorcisms. She, somehow, isn't too perturbed by this fact and tells him to intervene.The Father visits Joel and announces that his son is possessed. At first, Joel isn't too keen on letting the priest enter his house. But soon, he caves when he sees his son displaying otherworldly characteristics.A doctor is called in too who checks on Mason and reveals that she has heard voices inside his son.Joel allows them to perform an exorcism and his hallucinations heighten. The therapist visits him unannounced to check if Joel has been treating his son right.When she sees what is going on, she threatens to alert the authorities. Joel begs her and she asks him to agree to take her help.Joel does and that's when the truth is revealed. The therapist is actually a demon.There are three stages of possession. The first was for the demon to make its presence felt, which Joel did when he saw the hallucinations. The next step was for the demon to take possession. Joel was becoming quiet, strange, and behaving out of character.The third stage was assent. Without it, the demon would be unable to take Joel's soul. When Joel takes the therapist's help he unwittingly agreed to become possessed.The priests were not there for Mason but for Joel. During the exorcisms, they were calling out to him to come to their side, but Joel was waylaid by the therapist.In the end, the son has also grown up and is in danger of being possessed. (thanks to darkhorrortales)