The team investigate a woman who appears to be murdering her husbands for the insurance money.

Bayliss is primary on a major homicide of a young girl that gets national press coverage, Howard seeks help from a victim's ghost, Munch and Bolander investigate a homicide involving a couple unhappily married for 60 years while Bolander has a crush on the feisty coroner.

Crosetti and Lewis investigate the shooting of a fellow police officer, whom Crosetti regards as a son. Howard suspects a rabid Spiro Agnew fan of murder but ends up solving the Calpurnia Church case. Meanwhile, Bolander makes a friend whose death interrupts his date with Dr. Blythe.

Crosetti and Lewis crack the Thormann case, Pembleton and Felton spend a night out on their own searching for a Lincoln while the jumpy Bolander gives Munch a hard time over a double murder.

Bayliss has a new clue on his primary case and with Frank they interrogate a suspect who they believe to be the murderer of Adena

While Giardello is busy sending off an old friend to retirement Pembleton and Bayliss investigate the murder of a dog, Howard and Felton argue over whether Felton finds Howard attractive while dealing with a drug-related homicide and Bolander and Munch take Dr. Blythe's son on a ride along. Meanwhile, Crosetti takes care of the bed-ridden and blind Thormann.

Howard and Felton are in court over the Pony Johnson case, Crosetti and Lewis go head to head with the Secret Service and Bolander and Munch argue over drug legalization. Meanwhile, Pembleton gets an unexpected job offer.

Quitting smoking dominates the conversation ad behavior of the homicide detectives even as they solve what may be a gang-related killing of a 14-year-old boy. Lt. Giardello discovers a secret asbestos removal project on the third floor and confronts his superiors on behalf of his squad.

While pulling a graveyard shift on the hottest night of the year (with the AC on the blink) Bayliss brings in a potential suspect in the Adena Watson case, unfortunately he is twelve, Munch is angry after his girlfriend dumps him in the dark, Howard deals with a jumper in a Santa costume who tried to kill his wife with a water pistol while her sister is waiting for biopsy results, Crosetti deals with his daughter's sexuality, Bolander debates whether to ask Dr. Blythe out on a date and Felton and Lewis investigate the case of a mysterious candle lit every night next to the board. Meanwhile a baby is found in a cage and the team has to take care of it.