Mark Harmon is back on the case.

The NCIS alum, who departed the CBS drama in 2021 after 18 seasons, is set to reprise his role as special agent Leroy Jethro Gibbs for a special crossover event between the long-running procedural and its prequel series NCIS: Origins.

The back-to-back episodes, airing on Veterans Day Nov. 11, will see a young Leroy (played by Austin Stowell) and his colleagues “investigate the small-town death of a naval officer in the ‘90s” on Origins, according to a press release. The story will then continue on NCIS, where the case will be “unexpectedly re-opened” in the present day.

Despite his four-year absence, Mark, 74, hasn’t disappeared from the franchise entirely. He continues to serve as an executive producer on both shows while also narrating every episode of Origins, where he made a brief cameo appearance during the series premiere in 2024.

As for the Freaky Friday star’s decision to step back into Leroy’s shoes, he credited co-showrunners David J. North and Gina Lucita Monreal for making him a pitch he couldn’t refuse.

“I’m very proud of the storytelling that David and Gina are doing on Origins,” Mark said in an Oct. 28 statement. “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.”

CBS

Indeed, David and Gina teased that there will be at least one exciting update in Leroy’s life when the beloved character reappears on screen.

“Four years ago, Gibbs disappeared to Alaska to live a life of solitude,” they said in the press release. “We don’t want to give too much away, but let’s just say Gibbs is no longer alone.”

In the meantime, keep reading for a look at other stars who left their roles on hit TV series…

Virginia Sherwood/NBC

Mehcad Brooks, Law & Order

Mehcad Brooks shocked fans in 2025 when it was revealed he was leaving the NBC crime drama ahead of season 25.

Brooks, who joined the show in 2022, portrayed Detective Jalen Shaw for three seasons.

Bravo

Jax Taylor, The Valley

Jax Taylor announced he will not be returning to The Valley for season three amid growing concern from fans about his behavior during the show’s second season.

“Right now, my focus needs to be on my sobriety, my mental health, and coparenting,” the Bravo star—who is embroiled in a nasty divorce from estranged wife Brittany Cartwright—shared in July 2025. “Taking this time is necessary for me to become the best version of myself—especially for our son, Cruz.”