Starring Tim Robbins, Rachel McAdams, and Michael Peña. Rated PG. Opens Friday, September 26, at the Cinemark Tinseltown

Can a movie about returning Iraq veterans be whimsical and entertaining? The answer depends on your ability to put aside a sense of unfolding tragedy to enjoy the particulars of three sad sacks on a smartly written and well-acted road trip to somewhere.

The three in question are an older sergeant called Cheever (a very convincing Tim Robbins), going home with a back injury; the deadpan TK (Crash’s Michael Peña), wounded in his pride, which is in the groin area; and dumb-hick Colee (Rachel McAdams, pulling a nice Hilary Swank here), shot in the leg and carrying her dead boyfriend’s old guitar.

When their stateside arrival coincides with an airport blackout in New York, they snag the last rental car and head west. A few colourful stops later, they hit an affluent suburb of St. Louis, which really does turn out to be Cheever country; the sarge’s patrician wife (Molly Hagan) treats his presence as an unwelcome distraction from folding napkins. Meanwhile, Colee hopes her boyfriend’s parents will provide the home she doesn’t have. And TK—well, his goals are of a more carnal nature.

Director Neil Burger (The Illusionist), working from the understated script he wrote with Dirk Wittenborn (Fierce People), approaches the material with a lighter touch than might seem appropriate. But in choosing to focus on unique (and credulity-stretching) developments of three otherwise mismatched individuals, the filmmakers moved social commentary to the background. Still, when the trio ends up in Las Vegas, it’s implied that their overseas mission was a kind of extension of the casinos, churches, trailer parks, and McMansions that dot the American desert.