How Did Mark Harmon Return to NCIS for Origins Crossover After Exit?

Mark Harmon‘s highly-anticipated return for the NCIS: Origins crossover episode came as a surprise for some viewers following his shocking exit.

During the Tuesday, November 11, double feature, Harmon, 74, reprised his role as Gibbs in the opening scene of the prequel, where a present-day version of the character reflected on his life while in a cabin with a dog.

“Three decades, it’s a hell of a long time. That’s how long I put in on the job. Lately, I’ve been thinking a lot about those early days,” he reflected. “Back when I was still cutting my teeth. Over the years, the outside changes but inside you still feel all the same thing.”

Gibbs continued: “A long time ago, I worked with a dog that had a first and a last name. He’s a good guy, just like you. I was lucky. I worked with a lot of good guys.”

The rest of the episode followed a case that the Origins team tried to solve — only for an innocent person to take the blame. The conclusion haunted Gibbs and Franks (Kyle Schmid), which resurfaced in present day on NCIS.

After the falsely accused man broke out of prison, the NCIS team had to track him down and prove his innocence with help from a few familiar faces, including present day Vera, Woody and Philip. The case was ultimately solved for Franks, who had died, and Gibbs, who wasn’t seen again in the crossover.

Harmon’s return to the NCIS universe comes years after his exit.

“Four years ago, Gibbs disappeared to Alaska to live a life of solitude,” executive producers David J. North and Gina Lucita Monreal said in a statement before the episode aired. “We know how much fans have missed seeing Mark and have wondered what Gibbs is up to today. Well, on November 11, we’re so excited to announce that Mark Harmon will return as Leroy Jethro Gibbs in the Origins hour of the NCIS crossover event. We don’t want to give too much away, but let’s just say Gibbs is no longer alone.”

Harmon also addressed his decision to return, saying, “I’m very proud of the storytelling that David and Gina are doing on Origins. They continue to push boundaries and dive deeper into the characters’ backstories. They came to me with an idea for Gibbs that I liked, and it seemed like a good time to check in with him. I hope fans enjoy it.”

Harmon, who has remained an executive producer of both shows and is a narrator on the NCIS prequel, hasn’t played Gibbs on screen beyond Origins‘ 2024 pilot. The actor made his NCIS debut as Gibbs in 2003, going on to play the lead role for 18 years. His final appearance aired in late 2021, and Harmon moved on to work on the prequel alongside his eldest son, Sean.

“It wasn’t so much a decision to leave, but the right timing to push away a little bit,” he said on a July 2024 panel at the Television Critics Association summer press tour about his departure. “I was thrilled with the story line they came up with and how they handled the character. And the show continued on.”

Harmon was asked whether he could see himself returning in an onscreen capacity. “I have been asked that a lot,” he noted. “[But] I’ve always let the writers do what they want to do.”

NCIS: Origins airs on CBS Tuesdays at 9 p.m. ET.