 In the winter of 2005, the final bloody war between the fading Irish and Italian mobs of Boston took place, a mass slaughter that would change America s underworld forever. Showing both sides in an equal light with neither as a clear-cut "hero" or "villain" group, the film is a cold examination of how quickly pride, anger, and desperation can tear a city apart. The Winter Hill Gang has been a mere shadow of its former self since its now-infamous leader Whitey Bulger went on the run from the FBI in 1995. A few years later the Charlestown-based faction struck out on its own, and the two groups fought on and off again for some time until an uneasy ceasefire was called. Times are tough in a city where the working class they prey upon are replaced by increasing numbers of students and yuppies, and so when the latest boss Sean catches wind of an Italian heroin deal, he sees a chance to help bring the organization back to its earlier heights. While some are skeptical or nervous about such outright aggression against the stronger group, the young enforcer Molly Finn sees this as a chance for the gang to rise up, not realizing what the ultimate cost could be. The Leone Family based in Boston s North End is in an even worse situation. Their leadership completely crippled after years of federal investigations, those in command now find themselves behind the wheel of an organization they can t lead. Abandoned by Providence, with New York snapping at their heels, college dropout Sergio and his cousin Nick take a serious risk in hopes of setting things right. One Connecticut-born scumbag named Jimmy the Weasel, however, is fated to ruin everything.