The Conjuring: Last Rites prologue was originally "kind of a joke" scene involving the Warrens, a concerned mother, and a misplaced D&D book, says director

The Conjuring: Last Rites sees Patrick Wilson and Vera Farmiga's Ed and Lorraine face their "most dangerous" case yet, as they reunite with a demon they first encountered during their early days as paranormal investigators.

Warning! The remainder of this article contains major spoilers for The Conjuring: Last Rites!

Centering the Warrens in their final chapter on the big screen, the horror movie opens with a '60s-set flashback, in which a young Ed (Orlon Smith) and a pregnant Lorraine (Madison Lawlor) look into a haunting involving an antique mirror. When the spiritually-attuned Lorraine touches it, she has a terrible vision of an evil entity holding her baby – and suddenly goes into labor. Ed rushes Lorraine to the hospital, but the infant is stillborn. Ignoring the demon's dark presence in the delivery room, Lorraine prays to God to save the littlun, who's revived before being named Judy.

It's a heartbreaking scene that establishes the Warrens' connection to the film's overarching villain but according to director Michael Chaves, it wasn't in the script to begin with.

"The [scene] in that first draft was actually a very different sequence, and it set a very different tone," he recently told Fangoria. "It was actually a humorous scene where the Warrens have been brought in by a mother who's concerned about her son; it's the '80s, they're investigating his room, and they find a book. You think it's going to be some kind of occult or demonic witchcraft book, and it turns out to be Dungeons & Dragons.

"It was kind of a joke, but it spoke to the times, and there was a lot of charm to it, but what I wanted to do at the beginning of Last Rites was really set the stakes. Establish that we're not pulling any punches, and there weren't going to be any jokes to open it up. So I came into the studio and pitched the new opening, and everybody was excited and on board with that. That was one of the biggest things we implemented in the rewrites."

Chaves goes on to credit Richard Naing and Ian Goldberg for the changes, who tweaked David Leslie Johnson-McGoldrick's pitch when he wasn't available for the rewrites. He also highlighted that the film's "emotional core" was all Johnson-McGoldrick, and that the ending remained just as he wrote it.

What's curious, though, is that scare-filled prologues are pretty common place within The Conjuring Universe. The 2013 original opens with Ed and Lorraine coming face-to-face with Annabelle for the first time, while its sequel kicks off with Lorraine channeling the spirit of The Amityville Horror's Ronald DeFeo Jr. and seeing a premonition of Ed being impaled. Annabelle, released in 2014, starts with a violent home invasion.

It's interesting, too, to wonder how Last Rites might have set up the Warrens' connection to the demon at its center if it weren't for that opening sequence? If it did at all... Guess we'll never know.

The Conjuring: Last Rites is in cinemas now. For more, check out our list of the best horror movies, or our guide to the most exciting upcoming horror movies heading our way.