As NCIS struggles to come to terms with the news that one of their own is dead, Gibbs and the NCIS team attempt to find a motive for the killing while trying to deal with their own emotions over what's happened.

When a former NCIS Special Agent is found dead in a swimming pool at his home in Los Angeles, Jenny, Tony and Ziva travel to Los Angeles to attend the dead Agent's funeral. An encounter at the dead former agent's memorial service has Jenny greatly unnerved and soon realizing that the agent's death may not have been natural after all, prompting her to bring in an ally of the NCIS team to help out. As Jenny and Mike dig deeper into the case, they're unaware of the fact that the same group of assassins that killed the NCIS agent are after them while Tony and Ziva attempt to find Jenny who has ditched them while they were in Los Angeles but tragedy lies in wait and it's something that threatens to change the structure of the NCIS agency forever...

Jimmy Palmer becomes the target of a mysterious killer who only he can recognize.

Ziva's undercover assignment takes a shocking and deadly turn when the serial killer she has been tracking becomes suspicious of her.

When a mortar attack in Baghdad turns into a murder investigation, two members of the NCIS team are sent to Iraq to solve the case.

When the dead body of arms dealer La Grenouille surfaces, the NCIS team is put under investigation for his murder by the FBI and Jenny Shepard becomes the prime suspect.

When the NCIS team investigates a fatal dog mauling, Abby puts her career on the line to prove the dog's innocence in order to save his life. Meanwhile, Gibbs zeroes in on the secret Jenny is keeping.

When a high-tech naval radar goes missing, the NCIS team stakes out a warehouse to catch a suspected thief - but witnesses a murder instead. Meanwhile, Ducky keeps a secret from the team.

The NCIS team investigates when a Muslim Marine is found dead near a Mosque that is suspected by the FBI of terrorist recruitment. Their search is delayed when Ducky refuses to autopsy the Marine in deference to his family's religious beliefs.

The NCIS team pays a heavy price when they try to track down a Marine who believes he is still in Iraq. After a violent confrontation, the team realizes the Marine is the subject of a secret experiment.

The NCIS team plays babysitter to a 9-year-old boy whose father is wanted in connection with a cold case murder. Their search for the man, a trained survivalist, leads them into the wilderness where they discover the startling truth about his past.

The NCIS team's investigation into the assassination of a Navy Admiral takes an unexpected and emotional turn when they meet a woman searching for her missing husband, a political refugee from Africa.

When Gibbs agrees to help the childhood friend of his daughter, who died 15 years ago, he finds himself at the center of an emotional and soul searching journey into his past, which leads to a shocking and heart-stopping conclusion.

Gibbs and the team investigate a mysterious death aboard a top-secret naval research ship in the middle of the ocean, only to discover an abandoned ship and a deadly secret that could cost them their lives.

When the NCIS team is called in to talk a distraught naval officer from jumping off a rooftop, what starts out as an attempted suicide turns into a murder investigation for Gibbs and team.

Gibbs and his team identify a cadaver, mistakenly tagged a "John Doe," as a career felon with ties to a criminal mastermind capable of erasing unsavory pasts.

Gibbs and Lt. Mann unite for a joint investigation into the murder of a Marine Captain who had access to highly classified information. Things become complicated for Gibbs when a witness in the case turns out to be his ex-wife.

In autopsy, Ducky makes a startling discovery that leads to the search for a missing child. Meanwhile, Tony struggles to deal with his feelings for Jeanne.

The final showdown between the NCIS team and an elusive arms dealer reaches an explosive and deadly conclusion.