If Melissa Leo were Charlize Theron with artfully applied bags under the eyes, an Oscar nomination would surely be forthcoming for her terrifically truculent turn as Ray, a single mother of two boys who reluctantly teams up with an equally struggling Native American, Lila (Misty Upham), to smuggle illegal immigrants across the U.S.-Canada border. Like many first features that began life as shorts and were shot over two weeks with a Varicam, Frozen River can be ragged viewing. First-time director Courtney Hunt has astute visual command of the dreary landscape that frames these women's struggle to survive, but her abundant use of thin ice as metaphor and slathered-on pathos made me wince, and the movie careens uncertainly among gritty realism, sudden bursts of melodrama, and inspiration. Too many bad things happen, then too many good things, and I took bets with myself on the precise arrival time of the flowering of female solidarity between these two tigresses risking all for their cubs. That Ray's automaton hardness has its limits goes without saying, or Frozen River would never have been picked up by Sony Pictures Classics. But what sticks in memory is the unnerving lack of basic safety that comes with living on the financial edge, and being forced to take untenable risks.