Patrick Kenzie (Casey Affleck) introduces us to the tough neighborhood of Dorchester, an area defined by shattered dreams, broken families, tough luck and even tougher citizens. It's an area Kenzie knows well and that knowledge serves him well as a private detective. But when a young neighborhood girl goes missing, Kenzie and his partner/girlfriend Angie Gennaro (Michelle Monaghan) don't want the case. Gennaro insists that however it turns out, it will expose her to something dark and ugly that she doesn't want to face. But after pleas from the child's aunt (Amy Madigan), they reluctantly open an investigation. The case leads them to some dark secrets, family turmoil, police corruption and violence.
