The end of Insidious: Chapter 2 made it clear that any future films in the series would take place away from the Lambert family of the first two films, and would likely place the focus on a supporting player: Elise Rainier, the reluctant psychic played by Lin Shaye. While Elise does figure prominently into Insidious: Chapter 3, though, the film shifts back in time to a period a few years before Insidious to show her coming out of a self-imposed retirement.
The technical lead of this particular story is a high school student named Quinn Brenner (Stefanie Scott), whose mother recently passed away. Attempts she makes on her own to contact her mother’s spirit draw the attention of an unwanted demon, but not before Quinn reaches out to Elise, who is still mourning the recent death of her husband. Elise refuses to get involved at first, but the demon’s attacks against Quinn begin to escalate, and lead to Quinn being rendered helpless via two broken legs and a neck brace. Elise begins having visions of Quinn’s torture, and eventually comes to her aid.
Insidious: Chapter 3 marks the directing debut of Leigh Whannell, who’s also responsible for the screenplays for all three films in the series. He’s also a part of the series as an actor – more specifically, he plays ghost hunter Specs, who provides the series’ comic relief alongside Tucker (Angus Sampson). It’s telling how much he likes the returning characters, who give the film boosts of energy whenever they appear on screen. Unfortunately, he fails to develop the film’s new family. Quinn has little to do in the film but scream, particularly as she becomes immobilized, while her father (Dermot Mulroney) plays as clueless and in over his head. That’s about it, as far as character development for the new family goes.
Like the previous films in the series, Whannell also relies heavily on jump scares to provide horror. To his credit, Whannell does create some effective scares with the demonic character designs and smart use of aural misdirection. It may not be as effective as original series director James Wan’s work, but Wan’s now off making films in other genres (Furious 7 and the upcoming Aquaman), and Whannell makes for a good substitute.
With the low budget on these films, Insidious: Chapter 4 is almost inevitable. The end of this film sets up a potential new chapter, and the series could also choose to return to the “more current” timeline at the end of Chapter 2. Either way, the series seems to recognize that Shaye is their strongest element. A suggestion, then: if there has to be a new family in any future film, don’t worry about setting them up. Just go ahead and focus on Elise, and give the audience what they want: Elise standing up to the supernatural. It’ll make for a stronger feature.