As the NCIS team searches for Gibbs after wreckage from his boat is discovered, they find out he was tracking a serial killer with journalist Marcie Warren, who wrote an exposé on him.
Gibbs and Parker go on a road trip to find one of the serial killer's victims. Also, Agent Knight goes undercover at a large manufacturing company with ties to the murders.
When a hotshot financial advisor is found shot at a Naval station, NCIS investigates the case by interviewing the victim’s three-dimensional hologram of herself, which she created before her death.
NCIS is called in when Navy Chief Warrant Officer Rafi Nazar is suspected of trying to sell stolen classified Navy software used to pilot combat drones.
After a civilian research vessel in the North Atlantic picks up a small boat of wounded Navy officers, NCIS arrives on the ship and is forced to hide after discovering terrorists on board.
While investigating the death of an intruder at Quantico, Jimmy and Kasie are exposed to a deadly biotoxin. The NCIS team calls on Dr. Carol Wilson for help as they race to find the antidote.
As NCIS investigates the cause of death of a reservist Navy SEAL surgeon, they're forced to bring Vance's daughter to help with a highly dangerous mission.
NCIS investigates the apparent suicide of a retired Navy officer who was in Palmer and Knight's grief group; Torres gets a call from NCIS Special Agent Jane Tennant to come to Hawai'i.
The crossover continues on NCIS: Hawai'i S01E18 T'N'T (II).
When an infamous arms dealer, Reymundo Diaz, is released from prison and bodies start piling up, Torres is forced to face the repercussions of his actions during an undercover operation he worked on years ago.
