Team leader Special Agent 'G' Callen and his partner Sam Hanna are chameleons who have mastered the art of undercover operations. Special Agent Kensi Blye, LAPD liaison Marty Deeks, NCIS Assistant Director Owen Granger, and Operations Manager Henrietta 'Hetty' Lange, even Ops experts Eric and Nell get in on the action as the team works to stop a mastermind from bombing a train, solves a top-secret vaccine-related murder, and embarks on a rescue mission in Afghanistan to save one of their own.