What happened with Mark Harmon’s character on NCIS: Origins? Everything to know about his previous exit amid his surprise return

The NCIS universe witnessed an iconic crossover event as NCIS: Origins showed Mark Harmon appear onscreen after his brief cameo in the pilot episode of the series. As fans already know, the spinoff series has Austin Stowell playing a young Leroy Jethro Gibbs, when he was a junior agent in NIS Pendleton. The story of one case connected the younger and the older Gibbs across three decades in the crossover.

A quick outline of NCIS: Origins will remind fans that it is the backstory of Agent Gibbs of the original parent series. Played by Stowell, the spinoff shows the making of Agent Gibbs into the legendary detective that he later became, played by Mark Harmon. Moreover, Harmon is the narrator in the spinoff presenting his past life in a form of reminiscing and musings.

NCIS fans know that Agent Gibbs retired from the department and relocated in Alaska in 2021. While he is narrating his backstory on NCIS: Origins, he has no intention of returning to active work or his network. As such, a crossover showing Harmon’s Gibbs was a matter of eager anticipation for his fans. The recluse former agent appeared onscreen to narrate another case from the bygone era on November 11, 2025. This was Mark Harmon’s second onscreen appearance on NCIS: Origins.

Why did Mark Harmon leave NCIS: Origins?

As mentioned before, Mark Harmon played legendary Agent Leroy Gibbs on NCIS and retired from his role in 2021. However, in the spinoff of the parent series, NCIS: Origins, the older Gibbs presents the story of his younger days, his making and his struggles. Austin Stowell plays the younger Leroy Jethro Gibbs in the spinoff.

Mark Harmon was seen in the pilot episode of NCIS: Origins building a fire in Alaska, where his character, Gibbs, relocated after leaving NCIS. He was shown opening the spinoff by teasing a story that he did not openly tell before. As the series moved on to show Stowell playing the younger Gibbs, Harmon presented the background voice as the narrator.

He was later seen in the premiere episode jotting down his thoughts in a notepad. At the time it seemed that he may write a book later. Since NCIS: Origins is about the young Gibbs, Harmon was not expected to be present onscreen in the spinoff series. Incidentally, Harmon’s Gibbs left NCIS bureau in 2021, making his last appearance in the parent series in season 19 episode 4. 

On the personal level, work pressure of playing a central character in a military police procedural drama caused Harmon to struggle with physical demands. The actor also wanted his iconic character to have an exit arc while the character was still relevant to the storyline. However, the show’s decision to return with Gibbs’ backstory brought Mark Harmon back as the storyteller.

What was Mark Harmon’s NCIS: Origins crossover arc?

November 11, 2025, saw the return of Mark Harmon onscreen in a highly anticipated crossover event. As NCIS: Origins aired its season 2 episode 5, titled Funny How Time Slips Away, Mark Harmon’s Gibbs was seen sitting in his remote cabin in Alaska’s Naktok Bay, as a snow storm blew outside.

Gibbs fiddled with an old radio and tuned it past the weather forecast to play Willie Nelson’s song, Funny How Time Slips Away, highlighting his solitary life. He seemed to have rescued a dog from the storm and was shown talking to his new canine friend. He poured himself a drink as he declared that he thought a lot about his old days. He also told the stray that he felt the same things even after the long time gap.

He introduced himself to the dog while wondering what to name the pup. Harmon’s Gibbs then proceeded to remember his canine colleague, Special Agent Gary Callahan, three decades ago. With this tease to another case from the past, Harmon’s Gibbs transformed into Stowell’s Gibbs as a crime from the 1990s was revealed.

Whether Mark Harmon will appear on NCIS: Origins again remains to be seen. Meanwhile, the cases solved by young Gibbs will continue on the series as Harmon provides the voice and Stowell plays onscreen.

Continue watching NCIS: Origins every Tuesday on CBS as Agent Gibbs joins his mentor Captain Franks in solving cases in and around Pendleton in the 1990s.