Hugh Grant isn’t used to being mixed up in a screenplay quite as messy and perplexing as Heretic’s is. Although, he’s undoubtedly visited the outskirts of the M&P neighborhood in his 42-year stint as one of the most recognizable actors working in English-language films. Let’s just say the role of a creepy senior citizen terrorizing a couple of young women in his old dark house doesn’t immediately spring to mind as a likely career option for the onetime light-comedy leading man of Bridget Jones’s Diary and Mickey Blue Eyes, as he carefully navigates his dotage. People who fret over the durability of movie stars and the trendiness of genre pics are doubtless a bit dazed and confused about Grant’s association with latter-day fright-flick auteurs Scott Beck and Bryan Woods—makers of the popular A Quiet Place franchise, in which blind aliens hunt terrified Earthlings by sound. We keep picturing Grant cowering in his flat, trying to tame his stammering to avoid being eaten up. Silly stuff, but Grant needs to work like everyone else. Heretic isn’t quite as dumb as A Quiet Place, at least at first. A pair of young, female Latter Day Saints missionaries, Sister Barnes (Sophie Thatcher) and Sister Paxton (Chloe East), are out in the boondocks, ringing doorbells in a mountainous community somewhere—the exteriors were shot in British Columbia—and idly chit-chatting to kill time. The talk turns to penis size, then the porno industry, before settling down to the business at hand: promoting the faith, working off a list. Someone checked a box in a Mormon questionnaire. On Barnes and Paxton’s sucker list is a little house tucked into a hillside, where dwells a soft-spoken geezer named Mr. Reed (Grant), the type of Mid-Atlantic-accented fellow who favors sweaters, comfy house slippers, a cuppa tea and books—lots and lots of books. Uh-oh.  SPOILER ALERT: POTENTIAL AUDIENCE MEMBERS WHO WANT TO BE SURPRISED AT THE PLOT MECHANICS OF HERETIC SHOULD STOP READING HERE.  Mr. Reed’s house fits the profile of a movie murder scene to a T: eerie lighting, austere furniture arrangement, outré wallpaper and more. And he asks more “icky questions” than Barnes and Paxton’s typical customers, about polygamy, comparative religions and other touchy subjects. He won’t shut up, and presses slices of “homemade blueberry pie” on the increasingly uneasy women. They notice that their cell phones don’t work, and it turns out the walls are lined with metal. This odd old coot may initially seem like a routine house call, but it soon dawns on the Sisters that they, not Mr. Reed, are the goats. It is at this point, before the shock-cuts and the various ultra-grotesqueries popping out of the walls in Reed’s basement—yes, there’s one of those—that horror movie mavens will connect the dots all the way to the grisly end and wonder: Is that all there is? The answer to that is in Reed/Grant’s laborious method of questioning the questioners, a genuinely disturbing monologue combining menace and Grant’s patented bumbling humor, now veering off in sinister directions more suited to grim art-house character studies than youth-market popcorn shockers. In some horror movies sex is the goal line. Not here. Matched up against both women’s desperately wised-up parries—they’re trying to save their lives—is Reed’s pedantic history lesson on the One True Religion. He’s the true Nutty Professor, just as didactic in his mealy-minded way as the conversational calls to war of David Mamet or the ravings of the Marquis de Sade. As disheartening as it is to imagine, Grant’s performance in Heretic may give life to the logical, gloves-off, maniacal character lurking in the shadows of his namby-pamby roles in Four Weddings and a Funeral and the endless milquetoast rom-coms: the sadistic secret life of the pushover. Nice try, but it doesn’t really add up—unless Mr. Reed’s strategy is to bore his victims out of their minds before he kills them.  * * * In theaters