The LDS church has endured “The Book of Mormon” with reasonably good spirits, but it might find it harder to stomach “Missionary,” a mediocre proselytizer-turned-stalker thriller that believers might find especially disconcerting as it arrives almost simultaneously with the sunny documentary “Meet the Mormons,” which falls at the other end of the spectrum. While made with a reasonable degree of technical skill, its crude storytelling renders it at best cable-TV fodder.

Dawn Olivieri stars as Katherine Kingsman, a hard-working woman estranged from her husband Ian (Kip Pardue) and attempting to raise their son Kelsey (Connor Christie) pretty much on her own. She’s stumped trying to prepare the boy for football tryouts, however, and so when two Mormon missionaries stop by as they’re practicing, she’s initially irritated and standoffish. But one of them, Elder Kevin Brock (Mitch Ryan) shows Kelsey how to go out for a pass, and though it’s against the rules, his companion Elder Whitehall (Jordan Woods-Robinson) allows him to continue coaching the lad. Thankful for the help, Dawn is open to a prayer session with them.

Soon, however, the sessions between her and Elder Brock become far less prayerful. Without much foreplay they’re enjoying sex together—something that continues until Ian comes back into his family’s life, disrupting the dalliance. That’s the signal for Brock to turn possessive and menacing, leading to a confrontation between him and Ian that turns decidedly nasty—though not so nasty as the attempt by the now-maniacal Brock to kidnap Dawn and Kelsey to form the perfect unit. By now it’s evident that he’s unhinged: Dawn learns about a previous incident of stalking in his past, and he’s also had a run-in with some of his brethren. A protracted face-off in a junkyard finally settles the issue.

There are a few suspenseful moments in “Missionary,” most of them provided by Ryan, who’s fairly successful in portraying Brock’s appearance as a likable gentleman in the beginning and his brooding, intense stalker at the end. Unfortunately the transition between the two isn’t depicted particularly well, and the connection between him and Olivieri’s Dawn isn’t so much dramatically developed as simply taken for granted. And when it comes time for director Anthony DiBlasi to stage the final round of confrontations—first between Brock and Ian, and then between him and Dawn (with Kelsey a pawn in the game), he does so rather flaccidly, with the result that the conclusion comes off as predictable and staid. (DiBlasi served as editor, too.)

One can leave it to the LSD to dispute the accuracy of the picture’s depiction of its internal beliefs and practices; this critic is in no position to do so. As a movie, however, “Missionary” is little more than a pallid gender-reversal version of “Fatal Attraction” with an unseemly religious twist.