The Further has gone about as far as it can go. As introduced in James Wan and Leigh Whannell's playful paranormal romp Insidious, the inky black realm of spirits and demons known as the Further once offered a cheeky subversion of the standard haunted house yarn, where Wan's creepy creatures could crawl out of the dark and mug at the camera with abandon. It was a good gimmick; a definitive crux of the Insidious mythology and visual vocabulary (and a distinctly low-budget one at that.) Now, three films later, the Insidious universe hasn't grown much (neither have the budgets), and each new trip into the Further feels less alive, less imaginative, and certainly less frightening than the one before. 

Which makes Insidious: The Last Key a mixed bag. The follow-up is at its worst when it indulges in the reliable franchise tropes and at its best when it strains at the boundaries of what you expect from an Insidious film. With Adam Robitel (The Taking of Deborah Logan) at the helm, The Last Key looks distinctly different from the previous films (Wan directed the first two, Whannell directed the third), but there's also a unique quality to the story this time around (again penned by Whannell), which wisely leans in on Elise Rayner (Lin Shaye's fan-favorite medium), who has unexpectedly emerged as the ghost-hunting hero of the franchise.  

The timeline of the Insidious films is a little wonky, making Insidious: The Last Key both a sequel and a prequel. Insidious: Chapter 3 jumped back into Elise's backstory to show us how the intrepid psychic reconnected with her gifts and teamed up with her lovable pair of daffy sidekicks Tucker (Angus Sampson) and Specs (Whannell), and the Last Key picks up from there, serving as the bridge between Chapter 3 the first two films. Now that Elise is back in business, it's not long before she finds herself on the most challenging case of her life – one that leads her right back to her childhood home where abuse and tragedy, and the early emergence of her gifts, shaped her into the unshrinking paranormal powerhouse we know and love her as.  

Jump back to 2010, Elise receives a call from the new owner of her family home (Kirk Acevedo), who's all kinds of freaked out by the ghostly happenings in his new house. Dutifully, Elise returns to the home she escaped long ago to confront her demons once and for all – emotional and paranormal alike. The Last Key ties these two timelines together in surprising ways, connected by the spirits roaming the halls of Elise's old home and an evil presence she accidentally allowed into the world as a child. When the film is focused on how the spirit world bleeds into ours, there are lively, thrilling moments and some genuinely surprising set pieces. 

There's a grittiness and griminess to The Last Key's story, and its investigation into Elise's origin, that promises to evolve the franchise into new territories and occasionally it gets close. A particularly thrilling second-act reveal nudges The Last Key towards the crime genre in compelling way, and that throughline pays off with an elegant resolution. By investing in Elise, the film also offers a welcome perspective shift from the usual haunted house yarn, and Shaye continues to fill out the nuances of her character with the detailed hand of a craftsman. She's a true gem of a character actress and it's no small victory that she emerged as the lead of a box office powerhouse franchise -- not to mention the rarity of any film focused on the inner life of a septuagenarian woman, let alone a horror film. 

It's unfortunate then that The Last Key ultimately succumbs to franchise formulas in the end, returning us to the Further once again where we meet yet another intricately designed demon who ultimately doesn't make much of an impact. Once the film crosses over, the tension bleeds out like a punctured tire and The Last Key loses the momentum built up by the strength of the first two acts. There's plenty of places the franchise could go from here if the box office numbers merit another sequel, but the one place it shouldn't go is back to the same smoky, blacked out sound stages, which feel far too familiar at this point to conjure much of a fright. All the same, The Last Key thrives when it dares to do something new and contains some of the best moments since the first film, which will no doubt please the franchise diehards, and Shaye's deep dive into Elise makes the journey worth the somewhat disappointing destination.

Rating: C+