A Navy SEAL imposter's death gives the team a lead on a missing canister used to make deadly bombs.

Hetty's sudden resignation prompts Callen and the NCIS team to investigate the reason why she would disappear in the hopes of tracking her down.

The Special Projects team travels to Romania to search for Hetty, while delving into the history of the Comescu crime family, and their connection to Callen.

The NCIS team joins forces with the NSA to find the creator and controller of a software program linked to a cyber attack against the Department of Defense. Meanwhile, Callen continues searching for more information about his past.

Special Agent Sam Hanna is sent undercover as a bomb specialist as the team races to locate stolen explosives somewhere in the city. Meanwhile, to much protest, Hunter changes the dynamics of the team and has Callen partnered with Kensi and Sam with Deeks.

Callen and the NCIS: LA team confront their vengeful adversary, the Chameleon, when an undercover case ignites a deadly mind game orchestrated by the criminal mastermind.

The L.A. team is drawn into a deadly mind game against a master criminal motivated by Revenge.