Flashbacks reveal the murder case that first introduced young Gibbs to NCIS and his introduction to young, new-to-America Ducky.

Gibbs and Fornell's crusade to find the head of the drug ring responsible for Fornell's daughter Emily's overdose comes to a climax. Also, Gibbs and Vance finally let the team in on a case that has dangerous implications.

While pursuing a dangerous arms dealer, the team is shocked when Bishop is implicated in an old NSA leak while Gibbs and Marcie realize the killer they've been tracking may be onto them.

NCIS investigates the murder of a Navy officer who was killed while driving home a recently released inmate. Also, Gibbs helps Palmer deal with a personal trauma.

NCIS tracks a stolen laptop to the uncle of a young boy, Phineas, Gibbs’ former neighbor.

McGee and his wife Delilah's (Margo Harshman) Bahamian vacation turns into a high-stakes mission when a case NCIS is tracking of a dead escape room manager has ties to the island. Also, Gibbs fears the worst when his search for Fornell leads to blood.

Following a tip about smuggled weapons, Bishop and Torres engage in a shootout in a former sheriff's residence that's now a historical site, only to find themselves locked in abandoned jail cells there.

When members of an NCIS Regional Enforcement Action Capabilities Training Team (REACT) are killed during an explosion, NCIS Special Agent Jessica Knight (Katrina Law), the lone surviving member, helps crack the case using high tech body armor.

NCIS dives into the competitive world of food trucks after finding a man frozen to death in the back of one.

Evidence from the stabbing of a Marine Sergeant leads Torres to meet his father who left when he was a child.

The discovery of two dead bodies 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.

The team investigates a cyclist killed in a hit and run. Gibbs prepares to testify against a financial advisor who stole millions from his Navy clients.

NCIS uncovers a secret dogfighting ring, which leads to an unexpected move by one of the team members.

When Sloane’s name is discovered in Afghanistan at the site of an abandoned bus with a dead driver, Gibbs accompanies her on a trip to find a group of girls who were kidnapped from the bus. McGee, Bishop and Torres track down a hacker who emailed compromising information to the Taliban.

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.

Vance assigns McGee, Torres, and Bishop to Covid compliance duty at a foreign affairs summit, where they discover a link to another NCIS team's murder case.