As far as modern horror franchises go, Insidious is arguably one of the better ones in terms of both quality and scare factor. After bursting on to the scene back in 2011 with Insidious, the series suffered from a sophomore slump in 2013’s goofy sequel Insidious: Chapter 2 before delivering 2015’s surprisingly solid prequel Insidious: Chapter 3. The first two films were directed by James Wan (Saw, The Conjuring), but franchise screenwriter Leigh Whannell (he has written all four films) took over directing duty for the third installment. This weekend sees the release of Insidious: The Last Key, the sequel to the prequel of the first film, which is directed by series newcomer Adam Robitel (The Taking of Deborah Logan). The film provides the requisite number of jump scares and an affecting performance from Lin Shaye but unfortunately fails to add anything substantial to the franchise, making the existence of yet another prequel rather perplexing.

The film begins with a lengthy prologue that gives viewers a taste of Elise Rainier’s (Shaye, perfect as always) childhood in Five Keys, New Mexico. Due to the fact that she lives next door to a penitentiary that routinely executes convicts, Elise is frequently visited by the spirits of the dead, much to the chagrin of her abusive prison warden father (The Collector‘s Josh Stewart). One of these visits leaves her brother Christian traumatized and Elise locked in the basement with an evil entity that beckons her to unlock a hidden door. She does, and tragedy befalls her family.

Flash forward to 2010 (shortly after the events of Chapter 3), and Elise and her two tech assistants Tucker (Angus Sampson) and Specs (Whannell, pulling double-duty as actor-screenwriter once again) receive a phone call from Ted Garza (Kirk Acevedo), who is currently living in Elise’s childhood house. His claims of ghostly apparitions bring Elise back to the home she thought she had left behind. The paranormal investigation also reunites her with her estranged brother (Bruce Davison) and his two daughters (Resident Evil: Extinction‘s Spencer Locke and American Crime‘s Caitlin Gerard), making Elise’s past the primary focus of the film.

Whannell tries to tackle a lot in the film’s 100 minutes, but he is only moderately successful. The scenes of Elise’s childhood add a few layers to a character who has become the heart and soul of this franchise (despite dying at the end of the first film) and prove to be the most engaging, but they can’t help but come across as superficial. One has to wonder why Whannell felt this story needed to be told, as it doesn’t add anything particularly new to Elise’s character other than an abusive backstory. The script doesn’t linger on the abuse, but it also doesn’t give it the appropriate amount of attention that such heavy subject matter deserves, opting to gloss over a lot of it in favor of getting to the next scare. The present-day scenes with her brother and nieces don’t fare much better due to the fact that they too feel rushed and seem to exist solely to set the younger characters up for a future sequel (especially given one of the niece’s confessions in the third act).

The franchise’s trademark comedy from Tucker and Specs, a point of contention among viewers, is back in full force. Some scenes inspire chuckles, but others (like those in which Tucker and Specs flirt with Elise’s nieces) are cringe-worthy. I’ve never been opposed to the comedy from the duo in previous Insidious films, but it does get to be a bit much in The Last Key as it breaks any and all tension that Robitel has previously built up.

Many of the narrative proceedings in The Last Key are par for the course for an Insidious film, right down to the third act journey into the Further, the film’s version of purgatory. Lest you think that Whannell has run out of ideas, rest assured that he still has one or two tricks up his sleeves. There was one plot development that inspired a collective gasp from the audience. Had the film continued with surprises like that it would have earned a higher score. Sadly, the film doesn’t stick with this different direction and disappointingly reverts back to the expected narrative path. It’s a flash of innovation in an otherwise by-the-numbers picture.

If it feels like I’m being harsh on the film, it’s only because I am a genuine fan of this series (I have even grown to appreciate Chapter 2 over time) and expect more from it. For all of its shortcomings though, there is enough to like about The Last Key. Robitel proves to be a worthy addition, which shouldn’t come as much of a surprise considering his impressive work on The Taking of Deborah Logan, one of the better surprises to come out of 2014. He and cinematographer Toby Oliver capture the series’ aesthetic quite nicely (gotta love those tracking shots where a ghost happens to just be standing in the background) and manage to have some fun with the jump scares. One set piece in a tunnel is particularly clever in how it toys with audience expectations. Joseph Bishara’s signature violin score is curiously missing from the film however (curious because Bishara did compose the score for The Last Key), replaced with a somewhat generic score that diminishes the suspense. It makes sense that he would want to try something new, but his screeching violins are sorely missed.

One area where The Last Key does improve upon its immediate predecessor is in its villain. As embodied by Javier Botet (It) more menacing presence than “The Man Who Can’t Breathe” from Chapter 3. The creature design for the antagonist is top notch and Robitel uses it to its full advantage, even working in a nifty homage to A Nightmare on Elm Street. It’s a shame we don’t get to see more of KeyFace before the finale though, especially since the marketing has already spoiled his appearance. As great as Botet is, the film belongs to Shaye, who has made Elise one of the best final girls in horror history. It’s clear Whannell knows he wrote himself into a corner by killing her of at the end of Insidious, which is why half of the films in this series are prequels. It’s somewhat of a miracle that we have a female septuagenarian headlining a horror franchise in 2017, but I wouldn’t have it any other way.

Why we haven’t received a true sequel to Insidious: Chapter 2 (especially after that deliciously creepy cliffhanger) is beyond me, but here we are. Insidious: The Last Key is a serviceable prequel, but it is also the weakest entry in the franchise because it fails to do anything new with the property (Chapter 3 didn’t really do anything new either, but the story was more compelling). The Last Key opts to play it safe and offer up more of the same. If you’re looking for a fun jump-scare-a-thon that will keep your attention for 100 minutes, you could do a lot worse, especially when you take Shaye’s heartfelt performance into consideration. Given the way The Last Key ends, at least we’re all but guaranteed a true sequel to Chapter 2 if another installment is made. Maybe that one will inject some fresh ideas into this series.