Brian (Mark Ruffalo) and Paulie (Academy Award® nominee Ethan Hawke, Best Actor In a Supporting Role for Training Day, 2001) are two lifelong friends who grew up like brothers on the gritty streets of south Boston. They started early as street thugs living by the criminal code, doing petty crimes and misdemeanors that grew increasingly more serious. Eventually they fall under the sway of organized crime boss Pat Kelly (Brian Goodman). As Brian becomes increasingly lost in a haze of drugs and 'jobs,' he consistently disappoints his loyal wife (Amanda Peet) and their two sons. Torn between the desire to be a good husband and the lure of easy money, Brian must make the hardest choice of his life.

Mark Ruffalo is terrific in What Doesn't Kill You as a South Boston career criminal who since his early teens has done "errands" for the neighborhood crimelord and never considered any other way of making a living. It's the sort of performance wherein the actor so wholly inhabits the character that his every glance, stride, or hesitation is a glimpse into the guy's soul, even as the guy is a person of modest intelligence not given to complex self-expression. That's fascinating to watch (and this may be Ruffalo's career-best work), but it nudges us toward recognizing the film's limitations as well as its core strength. What Doesn't Kill You is an actors' movie; Brian Goodman, its co-writer and first-time director, is himself an actor and plays the gang boss. Virtually every scene is an occasion for actors to conspire in creating a believable texture of life going on. The cast all repay watching, especially Ethan Hawke as Ruffalo's lifelong pal and Amanda Peet as the long-suffering wife who seems to have stepped right out of a Southie kitchen. But there's only the barest outline of a screenplay. We get what every scene is supposed to be about, but they're mostly pieces of things, indications rather than scenes that flow and build; it's a little like seeing a feature-length compression of an entire season of The Wire. Although a foreword announces that "the story you are about to see is true," it's also a pretty familiar story as crime movies go. So, as a genre entry, What Doesn't Kill You disappoints, and its flashback structure--after an opening armored-car robbery scene heavy with dire portent--proves to be a bit of a cheat. Yet for all its shortcomings, the film compels sympathy, especially when it finally locates its eminently human heart during the final half-hour.