Sean Murray

A decomposed body is found in a tub of acid at a naval base, leading Gibbs to deduce that an imposter is serving on board one of the nuclear submarines.

The terrorist Bete Noir returns with a plan to attack the president. Gibbs and his team follow the clues to reveal his identity and find Kate, who has been kidnapped.

Gibbs and Kate suspect the CIA may be involved in the demise of a Navy officer, and believe that an espionage expert's work could lead them to the killer.

While investigating the disappearance of a Marine, the team discovers that three former members of the unit are dead, and they suspect the unit commander of being a serial killer.

When a fellow NCIS agent is murdered during the investigation of a cold case, the others vow to solve the mystery and catch his killer.