When a diamond heist results in an off-duty police officer being killed, Frank and the entire are determined to catch this cop killer.
The detectives investigate the death of a boy and his abusive guardian and discover a travel agency specialising in exotic trips for sexual predators.
A night at the opera leads to murder when a young violinist is pushed to her death and suspicion falls on the notoriously volatile conductor.
Goren and Eames are unexpectedly led to a serial killer when they investigate the death of an elderly black woman who appeared to have died from natural causes when in fact, she was actually the victim of a deadly physician.
The police break up a dog-fighting ring and discover a woman's finger inside one of the dead animals; detectives plot to trick an ambitious reporter.