Two master manipulators, writer-producer Nicholas Sparks and director Lasse Hallstrom, have joined forces to adapt Sparks’s “Safe Haven” for the big screen, but the Lifetime-quality woman-in-distress movie proves thin gruel indeed, even for aficionados of such stuff. The combination of turgid treacle and bonehead mystery culminates in a concluding twist of such complete goofiness that you almost have to admire the utterly shameless tugging at the heartstrings—almost, but not quite.

The story begins when a young Boston woman (Julianne Hough) boards an Atlanta-bound bus despite the determined pursuit of police detective Tierney (David Lyons). Flashbacks reveal that she bolted from a house, leaving behind a man’s body on the floor. Arriving in sleepy Southport, North Carolina, she decides to stay, taking a waitress job at a local eatery run by Maddie (Robin Mullins) and turning a remote, run-down cabin into home. She also meets handsome store owner Alex (Josh Duhamel), a widower raising two young kids, adorable little Lexie (Mimi Kirkland) and her older brother Josh (Noah Lomax), who’s finding it hard to deal with his mother’s death.

Though the woman, who takes the name Katie, bonds with Lexie, she initially resists Alex’s considerable charms, but that doesn’t last long. Soon they’re spending a good deal of time together, usually in icky montages set to bad pop tunes, though the original score by Deborah Lurie is no less schmaltzy. She even spends a day with him and the kids on the beach, bonding in ultra-cutesy style.

Of course the idyll can’t last, because, as periodic inserts show, Tierney is becoming ever more crazed trying to track the woman down, virtually terrorizing her elderly Boston neighbor for information and issuing warrants for her arrest on charges of first-degree murder. The reason why he’s so personally invested in the case is eventually revealed in flashback, but the plot takes the obligatory turn for the worse, romance-wise, when Alex notices one of Tierney’s wanted posters at the local police station, though the cops—dense, as usual—have overlooked it.

Throughout the picture there are references to a big Fourth of July fireworks exhibition that Alex regularly stages—and so it hardly will come as a surprise that the final confrontation occurs during it. It’s a pretty ugly business, involving both child endangerment and violence against women, which Hallstrom choreographs chaotically (if you want to see how this kind of thing can be done with style, check out the finale of Brian De Palma’s “Blow Out”). But to make amends he adds a coda centering on Katie’s only neighbor, Jo (Cobie Smulders), that takes the movie to new heights of absurdity.

The leads are photogenic—Duhamel sensitive and handsome, Hough petite and vulnerable. But both have what are essentially soap opera roles to play, and can’t get beyond what’s typical of that genre. Lyons, on the other hand, is stuck with a completely thankless part, and responds with a performance so over-the-top that it grows not only wearisome but faintly ridiculous. The kids are likable, but Hallstrom exploits Kirkland’s scene-stealing potential so ruthlessly that the result is slightly unseemly. The supporting cast is no more than fair, though to be just, none of their characters rise above stock.

Technically “Safe Harbor” is merely okay, with Terry Stacey’s cinematography often seeming murky and unfocused, especially in crowd scenes and cramped interiors. That might, however, be the result of the location shoot, which allows for some attractive backgrounds but also brings some difficulty for the crew.

Guys who are dragged to “Safe Haven” by their wives or girlfriends might consider their alternatives, even on Valentines Day, and try to sneak into the auditorium where less of a thorough chick-flick is showing instead.