Gibbs finds himself emotionally challenged when he agrees to investigate a crime connected to a friend of his daughter, who passed away years ago, and the investigation leads to a shocking conclusion.

The NCIS team goes on a stakeout in a warehouse to catch a suspected thief of a high-tech naval radar, but they accidentally end up witnessing a murder. Meanwhile, Ducky hides a secret from the rest of the team.

The dead body of La Grenouille finally surfaces and the entire NCIS is put under the investigation by the FBI, with Jenny as the prime suspect for his murder.

When a petty officer is found murdered, Gibbs learns about the mysterious connection between the disbanding of his team and the case.

When a murder investigation leads the team to Gibbs' hometown, secrets about his past are revealed.

During the week of Christmas, The Team is Forced to work overtime when they discover their prime suspect had been dead for 17 years.

The death of a boxer leads Vance to borrow the NCIS team and start investigating his death, while Gibbs digs into Vance's past.

The body of a Marine leads Gibbs and McGee to the NCIS OSP division in Los Angeles, where a murder investigation quickly climbs to a matter of national security in which the two offices must work together to resolve. Meanwhile, Tony begins to snoop into Ziva's personal life.

After a security breach at the SecNav's residence leads to the death of an ICE agent, Gibbs and the team are forced to work with ICE and the FBI to find his killer. Meanwhile, Tony finally comes face-to-face with Michael Rivkin.

The team discovers the bizarre death of a Marine and his two friends may be linked to their past, but its Gibbs who ends up taking a trip down memory lane.

A murder investigation prompts Gibbs and the team to play family counselor to his former mentor, Mike Franks, in the hopes of preventing a bloody international conflict.

While on the flight back from Paris, Tony and Ziva realize that their assignment to protect a government witness in an embezzlement case is in great danger when they learn that an assassin is located on the same flight.

Secrets arise when Gibbs former mother-in-law surfaces as a witness in a murder investigation.

DiNozzo finds himself increasingly captivated by a woman he's never met while investigating the murder of her brother.

The NCIS team has to find a young girl that was kidnapped, but their investigation turns into something else when her grandfather gets way too involved.

Abby becomes fixated on solving a murder; DiNozzo's latest fling leads to an interesting Halloween.

The dismembered fingertips and teeth of a murdered Marine are discovered in the stolen purse of a pickpocketer, launching NCIS on a mission to find a cold-blooded killer.

After new evidence reveals that the Port-to-Port killer has infiltrated the agency, the NCIS teams chase every lead in a race to track him down.

Gibbs and the NCIS team have to find answers regarding Tony's months-long assignment when an NCIS agent is found dead.

As the NCIS team continues its search for a missing Marine, Gibbs and Ziva travel to her last known whereabouts in Afghanistan. Meanwhile, Tony reveals his deepest fears and Gibbs is forced to relive events from his past.

During a routine stop for his morning coffee, Gibbs finds himself staring down the barrel of a gun, forcing him to question choices he has made in the past and present

Terrorism shakes the foundations of the Navy and NCIS to such an extent that Gibbs and the team face surprises that will devastate them.

With NCIS headquarters damaged by the bomb. Gibbs goes on the hunt for Harper Dearing and to bring him down once and for all.

When a helicopter crew is adrift at sea and later discovered on shore, the NCIS team must determine the cause of the crash and locate the missing pilot. Meanwhile, Tony and McGee channel their inner “Maverick” and “Iceman,” a la “Top Gun,” and Ziva challenges them to a dare.

It’s Christmas time and Tony DiNozzo can’t decide if he’ll be naughty or nice when his dad, Anthony DiNozzo, Sr., comes to town for a visit. Meanwhile, the NCIS team is “following the money” in order to solve a murder investigation, and Abby is bursting with excitement over all the holiday festivities.

On leave from NCIS while still grieving the loss of his wife and his kids’ mother, Director Vance discovers unexpected personal information that causes him to question everything.

The international manhunt for Eli David's killer turns into a federal witch hunt against Gibbs and the team, which questions their unconventional methods and threatens their future at the agency.

An explosion at a D.C. event that results in a casualty connected to the agency changes Parsons’ perspective on Gibbs and the NCIS team. Meanwhile, without badges, DiNozzo and McGee investigate the case as civilians, despite the case’s dangerous ties to each of them.

After Gibbs leaves mid-case to help his father reconnect with a former war pilot, Tony and McGee argue over who should run lead on the team’s investigation into the murder of a Marine Sergeant.

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.

Gibbs and Special Agent Pride chase leads in New Orleans after evidence points to a copycat of the infamous Privileged Killer. Meanwhile, Bishop sends DiNozzo a special souvenir from the Crescent City, as DiNozzo, McGee and the FBI continue to track political connections to the case from D.C.

The NCIS team investigates whether a fire on a U.S. Navy ship that served as a secret detention site for indicted terrorists was accidental or an intentional diversion for an escape. Meanwhile, Gibbs travels to his childhood home following news of his father’s passing.

Gibbs and McGee travel to Russia to safely escort home an NCIS computer engineer connected to classified intel, but their mission is compromised and they are forced to go off the grid while hunted by a Russian mercenary group. Meanwhile, the team in D.C. frantically uses every asset and inter-agency contact they have in an attempt to locate their missing team members.

After investigating the murder of a retired Master Sergeant, the NCIS team uncovers a fraudulent charity that preys on those searching for missing military personnel. Meanwhile, Bishop agonizes over the results of her probation evaluation, and Tony contemplates adopting a stray cat that followed him home.

After being shot, Gibbs fights for his life aboard a Navy hospital ship, while DiNozzo and Joanna travel to Shanghai to try and take down the Calling.

DiNozzo is reunited with his ex-girlfriend, Jeanne Benoit, when insurgents in Sudan attack a group of volunteer doctors, including her husband. DiNozzo and McGee travel to the crime scene for the joint murder and kidnapping case and join the search for the missing doctors.

After NCIS Agent Bishop is sent to Gitmo to gather evidence for a Navy chaplain murder case, she questions her previous work at the NSA. Also, Bishop’s brothers, John and Robert, visit for the Thanksgiving holiday and pester her co-workers to find out who she is dating.

NCIS searches for new leads after an undercover operation to apprehend a businessman who uses acts of terror to manipulate the stock market is compromised. Also, Bishop and Qasim find a break in the case together.

When a Navy SEAL vanishes during an unsanctioned trip, Gibbs, McGee and Torres travel to an unpopulated area in Paraguay that's teeming with violent rebels.

Season 15 begins with the NCIS team tirelessly searching for Gibbs and McGee two months after they were last seen fighting an elusive group of rebels in a Paraguay jungle. Meanwhile, Vance and Torres are summoned to a congressional hearing regarding the fallout from the Paraguay mission.

Sloane is adamant that a man who held her hostage and tortured her years ago in Afghanistan, and was believed to have been killed following her rescue, is alive and in D.C. Also, Vance and Gibbs fear Sloane is willing to risk everything to destroy this man.

One month after Director Vance was kidnapped, Gibbs is assigned the role of acting director in his absence while the team searches worldwide for his whereabouts.

McGee reluctantly visits his high school after the unique computer password he used as a teenager is linked to the murder of a department of defense contractor. The case escalates when an intruder breaks into McGee’s home in an attempt to steal his archaic high school computer.

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.

Former FBI Agent Tobias Fornell pleads with Gibbs to do whatever is necessary to take down drug dealers and suppliers in the area after his daughter, Emily Fornell, is hospitalized from an opiate overdose. Gibbs is haunted by the personal aspects of the case and his history with vigilante justice.

With their lives in danger, Gibbs and Ziva’s rogue investigation takes an unexpected turn when a possible terrorist plot is revealed.

After a petty officer’s son is found murdered at his “welcome home from prison” party, evidence suggests Kasie’s lifelong best friend, Dante Brown, is the suspect.