The Machine leads Reese and Finch to their new POI: an enforcer for the Irish mob named Riley Cavanaugh. Initially, Reese suspects Riley to be the perpetrator when the boss, George Massey, orders him to kill Annie Warren, the widow of a former mobster. However, when Riley kills George's son to protect Annie, it's revealed that Riley and Annie are in love, and our heroes now have two people to protect from a vengeful mob boss. Carter runs interference with the cops at Reese's request, keeping them off of Riley's trail just long enough for him to figure out his plan. George then puts out a hefty bounty on the lovers, making them the target of every thug in the city, and Finch is forced to go to Elias (ep. 106, 119) for help. Elias calls most of the would-be bounty hunters off, save for one--a man named Ochoa, who tracks them down and takes Annie. Reese squares off with Riley, then convinces the mobster to accept his help if he wants to save Annie. They track Ochoa to one of the properties George uses for wet work, then engage in a massive shootout with a large number of mobsters. In the fight, Riley tells Reese to get Annie to safety, then he kills George, only to later be killed by Ochoa himself. After putting Annie on a train out west, Reese tracks down Ochoa and exacts revenge, removing one more killer from the streets.