Another theme that is prevalent throughout the film is the idea of grief and loss. Josh's experiences are deeply rooted in his own traumatic past, and the film explores the consequences of unresolved grief and the devastating effects it can have on a family.
Insidious Chapter 1 succeeded because it played with audience expectations. Most haunted house movies end with the family moving away. In Insidious, the Lamberts do move, only to find that the entities have followed them. By making the haunting personal (attached to the person rather than the location), Wan and Whannell raised the stakes and made the threat feel inescapable. insidious chapter 1