Producers: Arielle Elwes, Veronica Radaelli, David Chackler and Joel Michaely    Director: Mitzi Peirone   Screenplay: Mitzi Peirone and Guinevere Turner   Cast: Bella Thorne, Rebecca De Mornay, Joy Rovaris, Jan Luis Castellanos, Dylan Flashner, Bart Johnson, Joel Michaely, Erica Dasher, Juliet Sterner, Frank Whaley and Ryan Phillippe   Distributor: Quiver Distribution

Grade: C-

Whatever virtues Don Roff’s 2021 novel “Clare at 16” might have—it’s certainly appealed to some fans, evidenced by its having already spawned two sequels—aren’t readily apparent in Mitzi Peirone’s adaptation, a murky, grisly tale of a young woman who sees herself as some sort of composite of Nancy Drew and Joan of Arc.

One of the few smart things about the movie is that it’s removed any reference to sixteen as being the age of Clare Bleecker, since while one could imagine many ways of describing Bella Thorne, who plays her, “sixteen years old” would certainly not be among them.  But Clare is still depicted as a student in a Catholic school, though apparently a college rather than a high school, and a very devout believer whose biblically-based mantra, endlessly repeated throughout the film, is “Everything I have said and done has been in the hands of God,” to which she often adds, “I was born to do this.  I am not afraid.”

What Clare does is rid the world of predators and malefactors, believing it her divine mission.  She’s an orphan: her father deserted the family when she was young and her mother (Erin Eva Butcher) has recently died, explaining why she now lives with her grandmother Gigi (Rebecca De Mornay), a former actress, in a new town and is a transfer student in the school where the choir still sings Latin hymns in an old-style chapel.  Since she was a child—some misty flashback montages fashioned by cinematographer Luka Bazelli and editor Patrick Sanchez Smith show her (Juliet Sterner) prowling about a forest and watching a creepy hunter drown what appears to be a fox—she’s been taking what she sees as her God-given duty to heart.  And she has regular visitations from Mailman Bob (Frank Whaley), the spirit of a man she once watched die deep in the woods, who now serves as a sort of ghostly confidant and conduit to the other side.

It’s not long before an opportunity to continue her work affords itself.  As Clare sits at the campus bus stop, a man in a passing car (Bart Johnson) stops and asks for directions to the place where he’s supposed to pick up his daughters.  Clare’s none too helpful, but climbs in the passenger seat when he offers her a ride.  He’s clearly a creep, up to no good, but Clare turns the tables on him and he winds up dead.

That brings attention from the local cops in the person of Detective Rich Timmons (Ryan Phillippe), who begins interviewing students, including Clare, for possible clues about the murder of the guy, a fellow named Joe, whose body she left in the car.  Her odd demeanor piques his interest, but he has no definite evidence against her.  Meanwhile she becomes best friends with her classmate Juliana LeBlanc (Joy Rovaris) and establishes a modus vivendi with queen bee Amity Liston (Erica Dansher); smoothie Wade Bradon (Dylan Flashner), Juliana’s ex, comes on to her, and photographer Truman Quirk (Jan Luis Castellanos) attracts her interest for the information his pictures can provide.  She’s even cast in the starring role of the campus play—Ira Levin’s “Deathtrap”—which flamboyant director Cole Edwards (Joel Michaely) decides to stage in cross-gender form, with her as Sidney, Amity as young Clifford and Wade as Sidney’s wife.  It’s a dumb idea, and its farcical nature doesn’t really jibe with the rest of the film.

Anyway, the play is of secondary concern to Clare.  She does some research on town history and discovers that dozens of girls have disappeared over the years; and she’s appalled that Timmons seems more concerned about the death of Joe than their fate.  When Juliana goes missing, Clare begins sleuthing herself and winds up at the ramshackle home of Joe’s brother Randall (also played by Johnson), where she finds out the ghastly truth and takes care of business in her own inimitable fashion.  A couple of further twists—one predictable, the other less so—end things on a note that could invite further installments, just as Roff’s book did.

But while the novel is generally pigeonholed as a YA book—and fans have described it as “fun”—Peirone’s treatment is a relentlessly grim, nasty piece of work, with even the streak of mordant humor providing little relief.  The visuals emphasize darkness, gloom, and a mood of implacable dread—and make James Wise’s production design and Louisville, Kentucky, where the movie was shot, seem pretty unattractive; moreover the frequent hazy montages, designed to reflect Clare’s inner visions, are deliberately unsettling, an effect complemented by Zola Jesus’ score.

As for the acting, it’s frankly all over the place, veering from Phillippe’s bored, sleepwalk turn to Michaely’s over-the-top campiness, and while it’s nice to see veteran De Mornay again, her penchant to go for broke in her few scenes is more than a mite grating.  But Johnson makes a perfectly scummy pair of bad guys, and Whaley adds a nicely quizzical tone to spectral Bob.  The younger players tend to archness, but among them Castellanos offers a more naturalistic turn.  And then there’s Thorne.  While admittedly too old for Roff’s idea of Clare, she works diligently to embody the character’s varied facets—her quietly meditative moments, her sharpness when challenged by Bob, and her physicality; Clare is no slouch in a fight, and Thorne and her stand-in make that clear.

In the end, though, “Saint Clare” seems an assemblage of discordant parts that never quite gel.  Perhaps it’s just strayed too far from its source.