Parsons gripes about his project; then a bomb explodes, killing the SecNav; Gibbs volunteers for a spec op, which takes him to Iran, where he runs into Parsons, and where they investigate. Tony tries to pursue Ziva in Israel. [Continued.]

A Navy petty officer dies of a gunshot in a park in Baltimore, Maryland; Gibbs and company investigate; at the scene Tony sees a clue and a man. Abby finds links, then the gang put the pieces together and nail the shooter. Tony nods off.

A Navy petty officer dies of gunfire in a park in Washington, DC; Gibbs and company investigate; Hollis helps. The gang find an accessory for hire to a terrorist. An explosion kills six and injures 22, including Delilah. [Continued.]

In an effort to find the terrorist Parsa, Gibbs and the NCIS team track down one of his cohorts using evidence from the drone attack. Meanwhile, an emotionally shaken McGee struggles with the ramifications of the incident.

An overturned van in Washington, DC, contains body armor, which Abby shows to be faulty and fatal; Gibbs and company find the body of the driver, then the source of the bad gear and the path to the troops in the Middle East. Justice wins.

Delilah finds a clue, which may help to solve the alleged death of a US Navy lieutenant, Kit, two weeks ago in Budapest, Hungary; then her boss orders her that she has never seen it; however, she surreptitiously speaks with Tony, McGee, and Gibbs, who sends Tony and McGee to check for chinchillas and to find evidence. Then Tony and McGee meet a man who claims to be an agent of the CIA, who tells a wild story to Vance and Gibbs, and who asks them to back off; still, though, Vance tells Gibbs and Ellie to continue pushing quietly. Abby and Jimmy, interpreting the evidence from the chinchilla hunt, paint a picture of Kit, who appears to be alive. The director of the CIA backs out and leaves the case to the NCIS. Delilah finds that Kit has left breadcrumbs; Kit encounters Gibbs and Ellie, and Tony joins them. Kit provides illuminating answers, and the gang finish putting the pieces together, so Tony and McGee grab the bad guy, and McGee and Delilah give Kit a ride.

A Navy Commander is murdered near the White House, it is learned that he was on his way to talk to the President. Gibbs and his team must determine if it is because of his relationship with the President or because of his marital problems.

After the body of a thief is found in a Marine's house, NCIS discovers the calling card of a terror group Delilah and the Department of Defense have been tracking. Margo Harshman guest stars.

When a petty officer is murdered, the crime matches a local serial killer's method of operation; Delilah and McGee prepare to move in together.

The team member's plans are interrupted when they discover discrepancies in what appeared to be an open and shut case.

Gibbs, Quinn and Palmer head out to sea when the body of a navy lieutenant is found on a destroyer during a tiger cruise.

The stress of McGee and Delilah's upcoming wedding lands Delilah in the hospital; the NCIS team investigates the mysterious death of a healthy, young petty officer aboard a Navy destroyer.

The team continues their search for Gibbs and McGee two months after they went missing fighting rebels in Paraguay; Vance and Torres are summoned to a congressional hearing regarding the fallout from the Paraguay mission.

Turkey day plans are on hold while tracking international arms dealer Andre Yorka, who recently murdered an MI5 officer who was Sloane's close friend. Also, Abby races Delilah to the hospital when labor for the twins starts 3 weeks early.

McGee reluctantly visits his former high school after the unique computer password he used as a teenager is linked to the murder of a department of defense contractor.

McGee and his wife Delilah's 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.

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.

NCIS investigates the death of a man on a cruise ship whose body is discovered in the ship's sauna.

The team investigate the death of a college student who was hit by a truck, after inexplicably stripping in the street before running into the road.