Starring: Nick Stahl, AnnaSophia Robb, Charlize Theron, Dennis Hopper, Woody Harrelson. Rated R.

Sleepwalking is oppressively grim, a torturous account of blue-collar misfits leading lives of penniless desperation and wandering aimlessly through the Northern California countryside in search of a way out. They are wounded, bearing the unmistakable scars of physical and psychological abuse, but Zac Stanford’s downbeat screenplay offers them little in the way of hope. The world is cruel and unforgiving, and happy endings have no place in it.

Charlize Theron, who also produced, plays Joleen, a decidedly unglamorous single mother who loses her home after the police discover marijuana growing in her backyard. Rather than take responsibility, she abandons her 12-year-old daughter Tara (AnnaSophia Robb) to run off with a trucker, leaving her beleaguered brother James (Nick Stahl) to assume parental duties.

James gives it his best shot, but it’s not long before Tara is taken from his cramped apartment by child welfare and placed in a foster home. From there, James takes matters into his own hands, rescuing her from one hell and unwittingly thrusting her into another – his family farm, where a violently misanthropic patriarch (Dennis Hopper) awaits.

Sleepwalking moves at an unhurried pace toward a denouement that hardly bears the promise of a brighter day but feels authentic in its bleakness; despite Stanford’s occasional flights of fancy, the film strikes few false notes. It is unflinching in its depiction of a family for whom desolation is a harsh but inescapable birthright, and if it feels at times like a death march, that’s no accident.

Theron, in a supporting role, has a commanding presence as a grown adolescent mired in an endless cycle of self-destruction, but Sleepwalking belongs to Stahl and Robb, who, at 14, carries herself with uncommon maturity. For his part, Stahl has rarely been better – his cheerless, understated performance suggests a man beaten into debilitating submission by a sadistic father but wanting, somewhat desperately, to forgive and forget. When he foolishly revisits his past, the familiar wounds open anew, with tragic results.