The team heads to LA to work with the team there to investigate a murder, which soon turns into something bigger. Meanwhile, Tony begins snooping into Ziva's private life. (Originally aired as NCIS Season 6 Epiosode 22.)

In Los Angeles, Gibbs and McGee continue working with the NCIS division in order to track a terrorist cell. Agent Callen goes undercover, while a psychologist uncovers the truth about the relationship between Gibbs and Agent Macy. Meanwhile, Tony fears that Ziva may not be loyal to NCIS. (Originally aired as NCIS Season 6 Episode 23.)

Hawaii Five-0 and the NCIS: Los Angeles task force team up in Hawaii when there’s a suspect on the loose who is threatening to release a deadly virus into the population. Series crossover part 1 is Hawaii Five-0 S02E21 . Series crossover part 2 is NCIS: Los Angeles S03E21.