
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.

Jimmy is torn between family and work after his father-in-law asks him to tamper with evidence in a current murder investigation; Ed's poker buddy offers to help with the case.

Director Vance is notified by the Pentagon that the nuclear submarine Gibbs and Bishop are aboard to conduct a murder investigation has gone radio silent.

Torres relies on his team's investigative skills after he wakes up on a dilapidated fishing boat and is covered in blood and unable to remember the last 12 hours.

Following an active shooter lockdown at a naval hospital, the team searches for a suspect who fled the scene; someone from Sloane's past is a key witness in the case.