Diane goes over to Bobby's and they sleep together, but Bobby is not impressed with her idea of a casual relationship and asks her to leave. She throws herself into her undercover work with Jimmy Liery and gets a strong idea of how he is moving stolen guns, but Jimmy has a nasty plan of his own in mind for her. Bobby and Andy catch a murder case where the prime suspect is Arthur Cartwell, a smart but obnoxious guy who was involved with the brutal murders in "Heavin' Can Wait". Neither cop wants to cut Arthur any slack, until a new witness puts the case in a different light. Lt. Fancy is rocked when his former foster son, Maceo, is arrested for running drugs. Fancy has to deal with Maceo's rude and sullen behavior, the evil actions of Maceo's biological mom, and worthless cop Ray Kahlins (from "Hollie and the Blowfish") to save Maceo from a long prison sentence. Greg asks Abby out on a date and she tells him she is a lesbian.