Da Vinci and Kosmo unravel the relationship between a young boxer and his mother's abusive boyfriend. Shannon and Leary pursue another cabbie murder. Patricia and Bobby Marlowe teach a group of medical students the nuances of crime scene investigation.

Da Vinci leads the search for the body of a boy who fell into a river. Is there something more to the death than just a tragic accident? Kosmo investigates a man whose wife has disappeared. A doctor is shot on his way to a clinic. Shannon and Leary chase down his killer.

A detained Chinese boat migrant dies while on a hunger strike. Da Vinci investigates. Shannon and Leary's prime suspect is a possible stalker as they continue their investigation of a double homicide.