Directed by Leigh Whannell, Insidious: Chapter 3 serves as a prequel to the Insidious franchise and follows a teenager who becomes targeted by dangerous supernatural entities after attempting to contact the dead. The film combines haunted house horror, paranormal investigation and spirit possession while expanding the mythology surrounding Elise Rainier and The Further.

Från IMDB:
A prequel set before the haunting of the Lambert family that reveals how gifted psychic Elise Rainier reluctantly agrees to use her ability to contact the dead in order to help a teenage girl who has been targeted by a dangerous supernatural entity.