The Naval Criminal Investigative Service's team, led by Special Agent Leroy Jethro Gibbs, conducts criminal investigations involving the U.S. Navy and Marine Corps.

S4, E16

Dead Man Walking

The NCIS team suspects foul play when a Navy lieutenant is the victim of radiation poisoning; Tony sees a softer side of Ziva.

S4, E17


When an explosion at a military cemetery's mausoleum reveals a cache of dismembered human remains, the team searches for a potential serial killer.

S4, E18


With a young Marine on life support, the team tracks his movements in the days leading up to his being left for dead.

S4, E19

Grace Period

Cassidy (Jessica Steen) blames herself when the team learns that a tip on terrorist activity was a trap that resulted in the deaths of two agents.

S4, E20

Cover Story

When a petty officer on whom McGee based a character for his latest book is murdered, McGee must figure out who could have accessed his secret manuscript.