Retired pugilist Bernard “Bang Bang” Rozyski (Tim Blake Nelson) is inspired to try his hand at training once he reconnects with his estranged grandson. While their training brings Bang Bang out of the hole he’s been living in, everyone questions his motivations, including an ex-girlfriend from decades ago, who was privy to Bang Bang’s meteoric rise in the sport in the 80s as well as the rivalry with his former opponent, her cousin and Detroit's Mayoral candidate Darnell Washington. Is Bang Bang merely passing down inherited rage, or is there true altruism behind his tutelage?