Austin Stowell will take over as a young Leroy Jethro Gibbs in NCIS: Origins, but not before the baton is officially passed. Here's what we know.

Mark Harmon, who played the 'NCIS' lead Leroy Jethro Gibbs for 18 years, is returning for an appearance on ‘NCIS: Origins’

It’s not supposed to be about old Leroy Gibbs — this is about his younger self coming up in the Naval Criminal Investigative Service — but Mark Harmon will appear briefly in the premiere episode of NCIS: Origins.

Mark Harmon once shared what it might take for him to return to the ‘NCIS’ franchise after his very peaceful exit.

Origins will explore the early career and life of Mark Harmon‘s Leroy Jethro Gibbs, this time portrayed by Austin Stowell. Though Harmon won’t be playing his younger self in the series, NCIS fans may be relieved to hear the actor will not only be narrating the series but he will also be making a special appearance in the premiere episode.

NCIS legend Mark Harmon is officially returning to the small screen in CBS's highly-anticipated spin-off, NCIS: Origins. Fans will be treated to a surprise appearance from Leroy Jethro Gibbs in the very first episode.

While North didn't confirm how Harmon will show up in the episode, he did leave the door open for more possible appearances in future episodes. "We are focusing on him telling the

The NCIS-verse has expanded, and Mark Harmon is still along for the ride. CBS announced in January that a sixth spinoff series of the long-running military-police procedural was on its way, and that the new show,