FBI agent Paul Smecker is on the trail of two vigilante brothers whose spiritual sense of right and wrong has turned Boston's streets red with blood. The victims are the villains and mob bosses that the justice system has been powerless to stop. Now, Smecker finds himself torn between whether he should catch the killers ... or join them.

FBI agent Paul Smecker (Dafoe) is on the trail of two vigilante brothers (Flanery and Reedus) whose spiritual sense of right and wrong has turned Boston's streets red with blood. The victims: villains and mob bosses whom the authorities have been powerless to stop. Now, Smecker finds himself torn between whether he should catch the killers ... or join them.

For the past eight years, the MacManus brothers have been living with their father on a remote sheep farm in Ireland, far removed from their past vigilante lifestyle. When their uncle informs them that their beloved priest has been killed by the mob, and they are being framed for the murder, the duo return back to Boston to, not only, bring justice to those who are responsible, but clear their names.