
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.

An NSA analyst who predicted a security breach works with the team when the Secretary of Navy was bugged during a confidential briefing.

The team investigates when the body of an NCIS facilities manager is found four months after she went missing; as the team faces mandatory psych evaluations, Gibbs is concerned about Abby's recurring nightmares.

The team finds a link between the boyfriend of Gibbs' ex-wife and a murder victim; Ellie Bishop tries to adjust to being on the team.

While trying to find the serial killer Gibbs was after, the NCIS team discovers another person has been tracking the case as well.