This fourth “The Conjuring” movie claims to be “Last Rites” and let’s hope that’s a promise.

While it’s highly likely the wildly successful Conjuring Cinematic Universe will itself continue — whether via scary nun, creepy doll or some other cursed object — the story of Ed and Lorraine Warren has been thoroughly wrung dry at this point and there’s no juice left to squeeze, as demonstrated in the dirge that is this final movie.

Credit where it’s due: The horror franchise has turned in some spectacularly scary and entertaining entries, anchored by performances from Patrick Wilson and Vera Farmiga as the married paranormal investigators the Warrens, based on an infamous real-life couple. Thanks to their presence, these films have been the best of the Conjuring series, exploring themes of faith and seeing as believing when it comes to both God and the Devil. These films have also offered portrayals of the Warrens that skirt any of their personal controversies, presenting them as blissfully married, heroic figures. Onscreen text might indicate that they were polarizing figures, but the films itself never engage with the scandals.

The first two films, directed by James Wan, ingeniously engaged with many variations on the idea of vision: physical, psychic and through a camera’s lens. Bravura cinematography aligned the audience point of view with Lorraine’s terrifying otherworldly dreams of hauntings, possessions and demonic presence. Michael Chaves, who directed the spinoff “The Nun II” and “The Conjuring: The Devil Made Me Do It,” has mostly upheld these requirements, though his approach is more bombastic than Wan’s elegant style.

Chaves is once again behind the camera for “The Conjuring: Last Rites,” with a script by Ian B. Goldberg, Richard Naing and David Leslie Johnson-McGoldrick that promises to deliver a final Warren case that devastated the family and ended their careers on a dark note. Instead, “Last Rites,” is merely a sluggishly routine send-off for the Warren family.

If you’ve seen a “Conjuring” movie, you’ll know what to expect and “Last Rites” doesn’t break with formula. While the film starts in 1964 with the harrowing birth of the Warren’s beloved daughter Judy, the plot largely takes place in 1986, an annus horribilis for the misbegotten Smurl family from West Pittstown, Penn., haunted by an antique mirror adorned with three carved baby heads, picked up from a swap meet. After a series of unfortunate eventsand increasingly violent visitations, a media frenzy surrounds them and the Warrens turn up to rid the house of creepy crawlies.

This time there’s the added complication of wedding planning: Judy (Mia Tomlinson) is about to get married, but she just can’t shake those pesky psychic flashes she inherited from her mother. Judy is the one who ventures to the Smurl household first. Then her parents, who had been hoping to hang up their ghost-hunting spurs, reluctantly join her for one last ride. Ax-swinging ghouls, terrifying baby dolls and demonic possessions ensue.

In “Last Rites,” the thematic metaphor for seeing is the mirror itself, suggesting that we need to look at the darkest, most terrifying parts of ourselves and not shut them out. Lorraine has tried to protect her girl from the life she has led, facing down the most terrifying demons, ghosts and spooks, but she can’t stop Judy’s destiny and the only way out is to not look away.

“Last Rites” extends the concept of a new generation by incorporating Judy’s fiancé, Tony (Ben Hardy), as a fresh member of the family business. His function in the story is a bit awkward and random, but required for the Warren plotline to end on a high note (that opening bit about the family devastation never seems to come to pass).

The heart of these movies has always been Wilson and Farmiga, and without them, the “Conjuring” movies wouldn’t be worth it. With this fourth movie, the Warren lore has been so thoroughly picked over, the tropes and rhythms now so ingrained, the jump scares end up feeling routine at best. Enduring the dour drudgery of “Last Rites,” it’s never been clearer that it’s time to give up the ghost.

Katie Walsh is a Tribune News Service film critic.