
Naval Criminal Investigative Service Special Agent Leroy Jethro Gibbs leads a group of colorful personalities in investigating crimes -- ranging from murder and espionage to terrorism -- that have evidence connected to Navy and Marine Corps personnel. The team includes MIT graduate Timothy McGee, Ellie Bishop, who specializes in international threat assessment, charismatic and unpredictable Nick Torres, and forensic psychologist Jack Sloane. Dr. Donald "Ducky" Mallard brings his vast experience in forensics into play to help solve cases.

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

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

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

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.