Andy and Bobby go to the hospital to investigate a bar robbery where a man intervened to prevent the robbers from raping a waitress and got shot. To their horror, the man who was shot and killed was Andy Sipowicz Jr. Andy can barely contain his shock, and Bobby resolves to work the case around the clock until they catch Andy Jr.'s killers. But Andy tells Bobby he wants the men who murdered his son dead, and Bobby is unable to respond before Andy races out of the 15th. He tells Sylvia and his ex-wife Katie the horrible news and they both collapse in tears. Bobby works the case with Diane and after the murder weapon is found near a construction site, he orders her to not come with him as he busts into a trailer two vagrants are living in, but ends up pistol-whipping one of the men after a gun was brandished. Diane rips into Bobby for his actions and he tells her what Andy said. They resume working well together and find out the vagrants were not involved in Andy Jr.'s murder. Andy makes funeral preparations and continues blaming himself for his son's death, saying Andy Jr. stepped into that situation without a gun and asking "What did I teach this kid?" Andy confronts Bobby and Diane and is furious when he learns that there are no suspects. Andy leaves Sylvia alone at home with their newborn son and goes to bar where he ends his long period of sobriety. In other sad news, Donna decides to leave the NYPD and take a job with Apple. Greg is clearly hurt but keeps his feelings to himself as the woman he loved walks out the 15th forever.