Cagney's car (a yellow Corvette) has been stolen and boy is she mad. She doesn't get much help from Mary Beth, who is convalescing at home and considering quitting for good. The good news is that the second half of the sergeants exam has a question about auto theft technique.The episode introduces Hector (El Vengeador). It is later learned that Cagney's nemesis Mansfield had him murdered for his role as a drug informant in the episode ""The Man Who Shot Trotsky
A two parter where Mary Beth discovers that she has a lump in her breast, but she refuses to talk about it or do anything about it. Chris finds out when Harvey gets worried and sneaks out to tell her. Chris finally convinces Mary Beth to see a doctor and then to get a second opinion. Meanwhile the detectives must find a missing child. Cagney thinks the kid ran away because the mother was unfit. The mother thinks that they would look harder for a white child. Finally he turns up in an underground passage and Chris goes in after him. Mary Beth goes in for her surgery, but Chris can't be there because she is taking the sergeant's exam. But she gets back in time to learn that the operation is a success
The 14th Precinct has done its paperwork so badly that everyone (except for Petrie) has to come in over the weekend and clear it up. but C&L discover a statute of limitations that's about to expire and they must serve the warrant that weekend. The paperwork doesn't get done. Petrie is no better off - Claudia makes him spend the weekend painting the place.