Home invasion is a mainstay of horror cinema. So is religion and its supposed tireless fight against demonic entities. When we turn both these tropes on their heads, we get Heretic, a horror film about unbelief, in which two Church of Jesus Christ of Latter-day Saints missionaries knock on the wrong door and find they can't leave. This clever chamber drama comes to us from the team of Scott Beck and Bryan Woods, who wrote A Quiet Place and directed 65. The deal Sister Barnes (Sophie Thatcher) and Sister Paxton (Chloe East) are weary from a long day of trying to convert unbelievers to their faith — and being taunted by teenagers who ask to see their "magic underwear." When they arrive at the home of Mr. Reed (Hugh Grant), a cheery fellow in a dorky sweater, the two young missionaries find him eager to discuss metaphysical matters. Their rules don't permit them to consort with lone men, but Reed assures them his wife is just in the next room, baking a blueberry pie. Barnes, a convert herself and the more worldly and skeptical of the two, side-eyes Reed's warm welcome from the beginning. But even naïve, bubbly Paxton soon knows something's wrong. The front door won't open, and the two women are trapped with a charmingly dithery man who is determined to test the limits of their faith. Will you like it? Given the way movies are marketed now, no one is likely to see Heretic without knowing its genre. But if someone did, they might be deeply confused for the first third of the film, which is simply a tense three-person drama with a lot of talk about religion. Beck and Woods' screenplay is savvy to all the angles of the situation: the young women's unease and strategic use of flattery and deference; the older man's dismay at the generation gap. The writer-directors make us wait a long time for the various tensions to explode into violence, ratcheting up the dread by degrees as cinematographer Chung-hoon Chung's camera tracks around the dim, frowzy rooms of Reed's home. Its restless movement expresses the audience's anxiety, while our two protagonists remain frozen in a strained facsimile of politeness. As for Reed, he has a show to put on for the missionaries, complete with props, lectures and magic tricks. Grant makes sly use of his comic talents in this…