
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 team investigates a series of crime scenes that appear to be copycats of previous cases; two of Gibbs' ex-wives show up at a crime scene.
A rescue mission in Syria reveals evidence that indicates an American was involved in a social worker's capture; DiNozzo's strange behavior is questioned.
An openly gay Navy lieutenant set to receive the Medal of Honor is murdered; Palmer gets ready for fatherhood.
A murdered Marine and alumnus of the military academy DiNozzo attended is found with a student's photograph in his hand; Bishop and her husband ask Gibbs and the team to dinner.