From murder and espionage to terrorism and stolen submarines, a team of special agents investigates any crime that has a shred of evidence connected to Navy and Marine Corps personnel, regardless of rank or position.
Gibbs and Fornell attempt to track down the leader of a drug ring who supplied drugs to Fornell's daughter. Also, the team deals with the case of a missing cadaver from the NCIS autopsy room.
Flashbacks reveal the murder case that first introduced young Gibbs to NCIS and his introduction to young, new-to-America Ducky.
The discovery of two dead bodies in a forest leads the NCIS team into the wild world of modern-day treasure hunting. Also, Gibbs and Fornell get deeper into their search for the opioid kingpin.