NCIS: Origins

When the team's trusted K-9 agent, Gary Callahan, is critically wounded at a crime scene, NIS races to track down the culprit while a surprising pre-Pendleton chapter in Franks' life is revealed.

When Dr. Tango is arrested for stealing human remains from a national park, Dr. Donald "Ducky" Mallard returns to assist the team in proving his innocence.

When the NIS Regional Director tries to transfer Mary Jo, she reconnects with an old friend from Atlantic City to help investigate the roadside deaths of two Marines.

When a lieutenant’s water-logged body is discovered with a potential connection to an international smuggling ring, NIS Panama agents are called in to assist, and Gibbs comes face-to-face with an old nemesis: Special Agent Dwayne Pride. Once the two are assigned to a dangerous undercover mission together, Gibbs must find a way to move on from their past.

When a marine captain shows up at Camp Pendleton exhibiting symptoms of a fatal virus, NIS goes on lockdown and Gibbs is forced to take charge. As panic spreads, the team races to determine whether it really is a deadly outbreak or something else entirely.

As the team discovers Gibbs’ drunken Vegas elopement with Diane, the newlyweds contemplate their future. Also, the team investigates a fatal movie theater bombing with a connection to the Pruitt compound where Mason is staying.

When Lala’s favorite CI is shot, the team joins forces with Oceanside PD to determine who was behind the attack. Also, Franks visits his brother Mason at the compound, and Gibbs’ relationship with Diane is tested when she gets a job in Los Angeles.

The team investigates the murder of a Marine who had recently been handpicked for a classified mission. Also, Wheeler’s personal life is upended, Lala is thrown by unexpected news from Vera, and Gibbs and Diane double-date with Randy and his wife.

When an anonymous tip leads to the discovery of a young Marine’s body at a chilling crime scene, Randy believes it could be connected to a previous case where a coin was left in the victim’s throat. Also, Franks tries to track down priceless packages meant for his brother, Mason.

Gibbs and the NIS team investigate the small-town death of a naval officer, but struggle to come up with justice. The crossover continues on NCIS S23E05 Now and Then (II).

Tensions rise when Franks’ estranged older brother, Mason, blows into town, desperate for help after hitting rock bottom. Also, the team investigates the robbery of a Navy bank while Lala, still struggling after her accident, makes a decision about her future.

Young Ducky is sent to Camp Pendleton to shadow the team while they work a case and, in the process, he reconnects with Gibbs after the two crossed paths years earlier.

When the body of a college swimmer washes up on the beach, the team must determine if it was an accident or murder. Also, Gibbs prepares for his first interrogation.

Gibbs and Franks investigate the disappearance of a young Marine connected to a mysterious compound with a charismatic leader, and Lala’s fate is revealed.

The team works the case of an investment advisor found dead shortly after her release from prison. Also, Mary Jo is left reeling by an unexpected development in her personal life.

The team investigates the brutal murder of a veteran who fell on hard times after serving in Vietnam, leading Franks to reflect on his own struggles following the war. Also, Gibbs considers a new path forward.

When the evidence room is broken into and significant cash goes missing, the team looks into a connection to a recent case. Also, Lala opens up to Gibbs, and Kowalski struggles to move forward.

The team investigates the death of a famed Marine commander's son, while a pivotal part of Franks' past involving his family is revealed.

As Leroy Jethro Gibbs prepares for his first Christmas without his wife and daughter, flashbacks reveal the unlikely journey that led to his first day on the job as a special agent.

The case of a missing woman who disappeared after a night of clubbing with a Navy seaman takes the team to Mexico, where they learn of a possible connection to Gibbs' past.

Gibbs and the team investigate the case of a Navy priest who was killed in the confessional booth and may have been targeted by mistake. Meanwhile, Randy shows Gibbs the ropes of working a protective detail while struggling with a personal situation.

NIS investigates the murder of a dementia-afflicted Jane Doe. Also, flashbacks reveal the first time Gibbs met Franks

Gibbs goes undercover for the first time with Lala as NIS works the case of a dead Navy seaman who may have been sharing top-secret intel that poses a threat to national security. Also, Lala struggles with her place on the team and an unexpected development in her personal life.

With the countdown on to an execution, Franks races to extricate the location of a missing body from a death row inmate and honor a promise he made to the victim's sister before time runs out.

Still grieving the loss of his wife and daughter, Gibbs helps the team work a case involving a missing girl. The moment that irrevocably changed Gibbs' life is revealed.

A murder near Camp Pendleton leads Gibbs and the team to a suburban mall in San Diego, where Gibbs takes matters into his own hands. Jackson Gibbs pays Franks an unexpected visit.

Gibbs and the gritty ragtag team continue their investigation at the fledgling NCIS Camp Pendleton office.

Gibbs starts his career as a newly minted special agent at the fledgling NCIS Camp Pendleton office, where he forges his place on a gritty ragtag team.