Paddy Colon (Nick Nolte) returns home one night to find the brooding Tommy Riordan (Tom Hardy) nursing a drink on the front steps of his house. Paddy’s estranged son soon sets his sights on competing in an MMA tournament. He enlists his father’s help to train for the event, as it offers a multimillion dollar purse to the winner. Meanwhile, Paddy’s other estranged son Brendan (Joel Edgerton) begins participating in MMA smokers to supplement his income. He also decides to enter the tournament, as the winnings would go a long way in getting him out of the hole. Old wounds are reopened as the Conlon men are suddenly thrust back into each other’s lives. In the end, their differences will be settled in the octagon.