“Heretic” opens with an unusual table setter: two young missionaries from The Church of Jesus Christ of Latter-day Saints Let’s discuss condoms and why some are labeled as large size when they are all pretty much standard size. “What else do we believe through marketing? » one asks the other.

This phrase will resonate throughout the film, a thought-provoking discussion of religion that emerges from the horror film. Despite a second-half slide and a feeling of imbalance, this is the rare film that combines lots of gushing blood and elevated discussion of the ancient Egyptian god Horus.

Our two church members – fiercely played by Sophie Thatcher and Chloe East – are wandering around trying to hide souls when they knock on the door of a pretty cottage. Its owner, Mr. Reed, offers a warm “Good afternoon!” » He welcomes them, brings them a drink and promises them a blueberry pie. He also wants to know more about the Church. So far, so good.

Mr. Reed is, of course, if you’ve seen the poster, the villain and he’s played by Hugh Grantwho doesn’t take the surly, dead-eyed route of Hannibal Lecter in “Heretic.” Grant is the slightly awkward, shy, mocking character we fell in love with in “Four Weddings and a Funeral,” but with a touch of menace. He gradually reveals that he knows a lot about the Mormon religion – and all religions.

“It’s good to be religious,” he says casually and promises that his wife will join them soon, a requirement for the Church. Warm touches in her home include a framed “Bless This Mess” embroidery on one wall, but there are also quirks, like her lights are on a timer and there is metal in the walls and ceilings.

Writer-directors Scott Beck and Bryan Wood – who also teamed up on “A quiet place” – have remarkably prepared us for an unexpected theological debate. Mr. Reed is reminiscent of a serious professor of comparative religion confronted by two naive missionaries armed with arguments that hide their own doubts.

Mr. Reed knows exactly where the weak points are and sticks the philosophical knife in. “What do you think about awkward questions?” » » he asks before addressing the Church’s position on polygamy. “Yeah, it’s a sketch, of course,” East’s Sister Paxton finally admits. Soon the discussion turns to the question of which religions are best marketed. Mr. Reed is, after all, confronted with a pair of walking, talking advertisements for Mormonism.

“Heretic” is so beautifully constructed and acted in the first half that you won’t really notice it when it turns into a horror film. You may be a step ahead of the missionaries, but not by much. Mr. Reed alternates between scary and funny, well-versed in Spider-Man and Voltaire, Radiohead and the Hollies, Wendy’s and Taco Bell. Grant gloriously used his natural charm as a weapon.

Mr. Reed has his own grand theory on religion and you will learn it. And he may or may not have some scary stuff in his basement. “This is all terrifying. It’s scary. I’m scared,” he says adorably, but he’s referring to organized religion. You’ll find him absolutely terrifying, a fanatical heretic in sheep’s clothing who can nicely imitate Jar Jar Binks from the Star Wars universe.

Beck and Wood take this fascinating premise as far as possible before it becomes a piece of airless theater. By the halfway point, the audience who came for the horror – not the lectures on religious marketing – is out for blood, and it will get some. The plot at the end is a murky, confusing, disturbing mess, a combination of too many ideas and no clear ending.

Grant, with his cozy cardigan and candles, is the attraction of the film, but there is excellent work from Thatcher and East, who try not to be afraid even when they are terrified. And these are not just innocent targets: they retaliate by criticizing Mr. Reed’s beliefs through gritted teeth.

The producers added a little marketing manipulation with “Heretic”, adding to some projections the flavor of blueberry pie with blood. Don’t get distracted. Keep your eyes on Hugh Grant and, well, pray.

“Heretic,” an A24 release that hits theaters Friday, is rated R for “some bloody violence.” Duration: 110 minutes. Three stars out of four.