NCIS LOS ANGELES Season 7 Episode 21 Photos Head of the Snake “Head of the Snake” – After Operational Psychologist Nate Getz (Peter Cambor) fails to check in with Hetty while working undercover on a mission linking organized crime to terrorism, the team learns he is working with an infamous crime leader, on NCIS: LOS ANGELES, Monday, April 11 (9:59-11:00 PM, ET/PT), on the CBS Television Network.