For a while it looks as if John Sayles might do for our largest state in Limbo what he did for the second-biggest in his masterpiece Lone Star. Set in contemporary Alaska, this independent veteran's latest deftly establishes the social, cultural, and personal details of his setting and characters; then he takes it all on a detour to nowhere. David Strathairn is lean, melancholy, and even sexy as Joe Gastineau, a former golden-boy fisherman who fell from grace with the sea after a fatal accident. Mary Elizabeth Mastrantonio gives her best performance yet (and demonstrates a decent set of pipes) as Donna De Angelo, an itinerant aging lounge singer between boyfriends and gigs and saddled with a bright but resentful daughter. The two hit it off, but just as it seems they might get their lives jump-started, Joe's shady brother Bobby (Casey Siemaszko) shows up asking a favor. What follows is either an exercise in self-deconstruction or a lesson in how not to write an ending; with Limbo, Sayles shows how high, and low, he can go.