“The Sixth Sense” opened the floodgates for thrillers to try all kinds of twist endings. “Safe Haven,” a “romantic thriller” based on a Nicholas Sparks novel, delivers two major twists: a rather cool one midway through and an epilogue shocker that teeters on sheer lunacy.

The film offers an already weird hybrid of love story and police procedural prior. But the closing creates head-scratching moments that even the cast doesn’t quite know how to handle. Fortunately, the Valentine’s Day release coasts on the beauty and charm of its stars before all heaven breaks loose.

Julianne Hough (“Rock of Ages”) portrays Katie, who is introduced during a tense escape from the law in Boston. Flashbacks imply she’s found a permanent way out of an abusive relationship.

A bus trip down the coast deposits her in a typical Nicholas Sparks sleepy North Carolina community, where Katie does her best to hide from prying eyes.

But that’s before she meets Alex (Josh Duhamel), a widowed store owner raising an adorable daughter (Mimi Kirkland) and sulky son (Noah Lomax).

Meanwhile, hard-drinking detective Tierney (David Lyons) obsessively tracks the fugitive Katie. Will she sacrifice her secluded safety for newfound love?

“Life is full of second chances,” advises her reclusive neighbor, Jo (Cobie Smulders).

“Safe Haven” fondles the touchstones of Sparks’ previous works, from “Message in a Bottle” to “The Notebook.” There’s dedication to a deceased spouse, secrets contained in letters, rain-soaked canoodling. But his centerpiece always emphasizes attractive lovers fighting all odds to remain together.

Hough continues to give appealing performances in mediocre projects. Radiant and spunky, she could blossom into something formidable if she ever landed a prestige role. Same goes for Duhamel (“Transformers”), although his single-dad character is more transparent than hers.

Swedish director Lasse Hallstrom (“Salmon Fishing in the Yemen”), a three-time Oscar nominee, brings a more confident eye to this material than is typically expected.

He grasps the look, feel and rhythm of a small town. (It’s enjoyable enough to drink in the woodsy, watery scenery of Southport, N.C., where filming took place.) He’s also skilled at directing child actors, capturing a naturalism to their performances that runs counter to most precocious tots who populate romantic comedies.

Yet Hallstrom is still held hostage by the script, courtesy of Leslie Bohem (“The Darkest Hour”) and Dana Stevens (“Life or Something Like It”). It’s hard to distract from this odd collision of genres no matter how pretty the tracking shots are.

“Safe Haven” all comes down to how captivating the central romance is (answer: sufficient) and how dippy the revelations are (answer: ludicrous). It’s a movie where common sense should have taken precedence over “The Sixth Sense.”