Winner of the Grand Jury Prize at this year's Sundance Film Festival, "Frozen River" plays rough with the emotions, but remains riveting, small-scale drama.

Veteran character actress Melissa Leo plays Ray Eddy, living in a trailer as a single mother of two sons in upstate New York. Her husband long gone, Ray Eddy struggles to get by with a dollar-store job, but recognizes opportunity, however dangerous, when she joins another woman smuggling immigrants illegally across the frozen river, and to a presumably better life in the United States.

The activity is fraught with risk, not only legal, but also physical, as a heavy car makes the jaunt across that ice-caked river. Meanwhile, she must also tend to her two sons, and by nature of her choices, puts them at risk.

"Frozen River" is quality drama, full of interesting characters, with a commitment to realism. Bypassing beauty and tidy plot points, the film is quietly affecting, and with a terrific performance from Leo as the sad mother determined to survive.

B+ "Frozen River"

Starring: Melissa Leo, Misty Upham, Charlie McDermott

Director: Courtney Hunt

Studio: Sony Pictures Classics

Rated: R (for language and violence)

RT: 97 minutes