Set several years before the haunting of the Lambert family, Leigh Whannell's directorial debut in the Insidious franchise shifts focus to a new victim of the terrifying Further. Teenager Quinn Brenner (Stefanie Scott) is desperate to contact her late mother, seeking the help of the reluctant psychic Elise Rainier (Lin Shaye). Despite Elise’s warnings to stop reaching out, Quinn’s desperate attempts open a door to a malevolent, gasping entity that will stop at nothing to possess her. As Quinn’s health deteriorates and her family is terrorized by this unseen force, her grieving father Sean (Dermot Mulroney) is forced to believe the unbelievable. With time running out, Elise must conquer her own deep-seated fears and the darkness that destroyed her husband, assembling a team of paranormal investigators to confront the demonic specter and rescue Quinn from a fate worse than death. This chilling prequel maintains the series' signature tension and terrifying jump scares, exploring the origins of Elise’s psychic abilities and the tragic event that drove her into retirement.