Located in Los Angeles, California, there is a clandestine division of NCIS called the Office of Special Projects, or OSP.

Their mission is to go deep undercover where necessary in order to capture those criminals that threaten national security.

NCIS: Los Angeles follows a tight knit team within the OSP that consists of G Callen, the chameleon and his partner Sam Hanna, who also happens to be a surveillance expert. Also on the team are Kensi Blye, the adrenalin junkie and Nate Getz who is a phsychologist. Nate's remit is to ensure the continued mental wellbeing of the team as well as to give an opinion with regard to the current mission.

The team have access to the latest technological developments but they also have to manage their own budget. The Operational Manager, Henrietta "Hetty" Lange manages this side of things as well as being overall team boss.