All reassess their personal lives after witnessing a chance reunion between two long-lost lovers in the emergency room; Karev treats a troubled teen; Meredith shares her suspicions with Cristina.
The BAU pursues Billy Flynn, who has kidnapped Det Spicer's daughter and continues his murder spree throughout the city of Los Angeles.
When Los Angeles is swept by a series of blackouts, a serial killer uses the cover of darkness to commit murders.
Jason and the team are assigned to bring back an American soldier who was captured after deserting. However, the team have mixed feelings about their task.
The murder of a petty officer in a small town outside DC prompts NCIS to once again work with The Sherlocks, a privately funded investigative team.