James Wan’s Conjuring universe gets an Eastern European expansion team in The Nun — the fifth film overall but the prequelest prequel yet, set in a crumbling Romanian abbey circa 1952.

Like Annabelle and its own prequel (Annabelle: Creation) before it, The Nun (directed by Corin Hardy) is an undercard entry. Billed as “the darkest chapter in the Conjuring Universe,” it’s the bloody backstory about Valak. That’s a bad-guy beast wrestled with by the paranormal-investigating Warrens in the main-event Conjuring films that Wan bothers to direct himself.

(Side note: Whether he forges them from the ground-up or enters on the penthouse floor, any and all Wan-affiliated franchises have seen their best entries directed by someone else — Saw II, Insidious: Chapter 3, almost any other Fast & Furious movie. In this universe, surprisingly, it’s Annabelle — the only one yet to make memorable meta-textual hay of the era in which it’s set. And is Aquaman going to be better than Wonder Woman? Yeah, see what I mean?)

Hardy generates fairly foreboding atmosphere in his cap-tip to classics of gothic horror. Every shadow or shaft of light is faithfully reproduced on this Blu-ray release, which at least does well by Hardy’s visual scheme. Like any Conjuring outing, there is too much sincerity to the craft for a full, round thumping. And while The Nun is easily the series at its most rickety, at least it’s mercifully brief. (At 110 minutes, Annabelle: Creation felt long enough to make you wonder if there were a Conjuring film about, say, an evil bar cart, whether it would run three hours.)

Casual viewers will appreciate a “previously on The Conjuring” segment that opens The Nun — recapping the evil shenanigans that occurred when we last saw Valak, sort of the Thanos of this series, donning his disguise as a fanged, pale nun. (Bonnie Aarons reprises her role.)

Valak must be Romanian for “demon who taunts a Farmiga every quarter-century.” In The Conjuring 2, it was Vera Farmiga. Here, it’s her sister Taissa as Irene, a novitiate on the cusp of buying the Catholic cow before the Vatican conscripts her to join Father Merr … sorry, Father Burke (Demián Bichir) in the investigation of a nun’s violent suicide in Romania. Perhaps not trusting us to understand this nun hanged herself after explicitly conveying what she’s done, The Nun doubles down to show her corpse’s face pecked out by a murder of crows.

All the better with which to engage the Dolby Atmos speaker channels, I suppose. They receive the usual high-intensity interval training you expect of lossless audio in horror — demonic snarls, clanging bells, cracking bones, thunderbolt and lightning not so very frightening me. There’s also impressively rumbly bass that will, if not rattle nerves, at least flap your cheeks.

By now, most of us could probably perform a citizen’s exorcism with a few In nomine Patris et Filii et Spiritus Sanctis of our own. Hardy, too, recycles the usual motions, namely the one in which the heroes must be repeatedly rocketed back into stone without shattering vertebrae. At least there’s one scene guaranteed to screw with those who suffer from claustrophobia, and it’s also just like the Catholic Church to think it can toss down some lye on a gateway to hell opened by an occult-obsessed duke. (Don’t call it a convent. It’s been here for years.) But The Nun just descends into more surprise grabby-hand scares than a Jaycees haunted house and hinges on a plot twist that takes communion to an unexpectedly amusing new connotation.

Special features are scarce, the biggest draw being 12 minutes of deleted scenes. Most amount to little beyond easily excised connective tissue or alternate character introductions. There are a couple of modestly spooky moments with the Nun creepin’ and an admittedly uproarious Night Ranger reference you just know screenwriter Gary Dauberman was loathe to lose.

Three featurettes round out the package: “The Conjuring Chronology” traces the saga’s (so-far) 25-year timeline from 1952 to The Conjuring 2’s 1977, which you know will be updated after (at least) two more films planned in the series. “Gruesome Planet” finds Hardy spinning tales of how real-life Romanian locations possessed a direful energy all their own. “A New Horror Icon” is a self-congratulatory victory lap for Valak in which Hardy just sounds so pleased with himself.

To be fair, it’s not just Hardy. “Nobody had made a great gothic horror movie in a long time,” says one of the producers during “Chronology.” Delusions can be a powerful fright all their own.