Starring Josh Brolin and Kate Winslet. Rated PG. Now playing

The basic storyline for Labor Day could double as a Harlequin romance. An escaped convict named Frank (Josh Brolin) takes refuge in the home of Adele, a reclusive single mother (Kate Winslet). In less than a week, Frank awakens Adele’s simmering passion while winning over her son Henry (Gattlin Griffith), a lonely teen who craves male attention. Even if that male happens to be a convicted murderer.

Directed and adapted for the screen by Jason Reitman, Labor Day is based on the novel by Joyce Maynard. Reitman’s screenplay flirts with all sorts of dangerous clichés. There’s a scene where Frank ties up Adele, which is clearly meant to be erotic. In the hands of a less confident director, this could spell disaster. And yet Reitman has a way of making tension seem both subtle and tantalizingly constant. Despite the far-fetched plot, he refuses to strike a false note.

The same holds true of the acting (including the evocative narration supplied by Tobey Maguire as the adult Henry). That said, Josh Brolin has the toughest job. He plays a man who accidently killed his young wife in a fit of temper. Despite this, he comes across as gentle, nonthreatening, and even wise.

Hard to believe? Maybe. But Brolin makes a convincing case with a straight-ahead performance that refuses to rely on even a shred of misplaced charm.

One of the true pleasures of Labor Day is watching Frank instruct Henry in the life skills he needs for adulthood. He teaches the boy how to change a tire, bake a pie, and throw a baseball. All things that Henry’s father, who has long since remarried, is too preoccupied to do.

Frank quickly slips into the role of Adele’s surrogate husband, doing everything from repairing the ramshackle house to calming her jangled nerves. It turns out to be a love story that insists on building naturally against all odds.

Winslet turns in a typically strong performance. Deeply wounded by life, Adele puts her faith in a situation that’s bound to change. Despite this, we can’t help hoping it never will. And that’s ultimately Labor Day’s biggest strength.