Sleepwalking stars Charlize Theron -- but she disappears from the screen for about two-thirds of the film. It's set in the American West -- but shot in Canada. It's about family, pain, loss, renewal -- all of which are discussed, and discussed more elegantly, in other films at Sundance this year. It even has what's become a fairly standard-issue Sundance finale, as a character hits the open road with a bright future ahead of them, aside from the murder rap in their rear view mirror. It's not that Sleepwalking is bad, per se; it's just that it's inert, a space-and-schedule filler that can now put the words "Sundance Premiere Selection" on the DVD box when it goes straight-to-video.

Joleen Reedy (Theron) has one of those lives where all the things that go wrong keep her harried and distracted enough to not notice how many of them are her fault. She's been thrown out of her house because the cops have seized her boyfriend's on-site marijuana gro-op, and she and her daughter Tara (AnnaSophia Robb) move in with her brother James (Nick Stahl). Joleen doesn't even try to get back on her feet -- or, rather, she figures the best way to get back on her feet involves leaving town in pursuit of another man; Tara's left with James, and his strained life implodes under the stress of trying to care for an 11-year-old girl.

And so James and Tara hit the road, traveling and working and eventually winding up at the family farm, where the Reedy family's patriarch (Dennis Hopper) welcomes them in and gradually makes them feel less and less welcome. James and Tara have bonded on their trip -- Tara's finally enjoying some adult supervision, while supervising Tara makes James feel like an adult -- but his father's coarse, brute ways are threatening them both.

Directed by William Maher from a script by Zac Stanford, Sleepwalking doesn't lack craft in the direction; there's a moment where Stahl finds Robb to explain they'll be staying in one spot for a while, and the shooting of the glassed in pool area solarium is captured with life and light; moments like that in the film, however, are few and far between. And the material's so mired in familiarity -- bad dad, sad sister, brooding brother, disappointed daughter -- that none of the actors can break the movie out of that cage.

Theron's name should be enough to get a few people to watch Sleepwalking, and she's good when she's on-screen -- Joleen is the kind of woman who says "I got a lot of options ..." even though she doesn't quite believe it herself, who flips the cops off as she drives away from their seizure of her home in a car with three different shades of body paint. But at the same time, there are long stretches where she's off-screen; the film focuses on Stahl and Robb. And both Robb and Stahl are very good. "If you could go anywhere in the world right now," he asks her, "where would you be?" Her reply -- "I don't know." -- comes from the wounded heart of a real character. It might be harsh to call Sleepwalking inert, but there's really nothing in it that feels new or necessary.