
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.

Personal plans are interrupted when errors are found in what seemed to be a straight-forward, closed case; McGee and Delilah argue whether work should be discussed during dinner.

NCIS investigates the unexpected death of a Navy reservist who was an investigative journalist; Knight and Jimmy's budding romance is put on hold when a vital organ transfer goes fatally wrong.

After an American couple is attacked in Iraq, Gibbs questions the lone survivor of a Special Ops group that was attacked months earlier in the same area.

A murderous psychopath taunts the team by leaving clues to the next victim's identity during the week of Halloween.