For years, NCIS fans have wondered what really became of Leroy Jethro Gibbs after he walked away from his badge and chose a quiet life in Alaska.

Now, Mark Harmon is officially stepping back into the spotlight — and Gibbs’ peaceful retirement may not stay peaceful for long.

CBS has revealed new details about the Season 3 premiere of NCIS: Origins, and the network is teasing that “ghosts” from Gibbs’ past will finally catch up with him in present day, shattering the quiet life he has built in Alaska.

And this isn’t just a brief appearance.

Harmon is set to appear onscreen as present-day Gibbs throughout all 10 episodes of Season 3, as part of a season-long mystery connected to his days at Camp Pendleton in the early 1990s.

That makes this one of Harmon’s biggest onscreen returns to the NCIS universe since leaving the original series as a regular in 2021.

The story will unfold across two timelines. Austin Stowell continues portraying the younger Gibbs in 1992, while Harmon’s older Gibbs is forced to confront something from those years that apparently never truly stayed buried.

Exactly what — or who — has found Gibbs in Alaska remains a mystery.

CBS has deliberately kept that part of the story under wraps, which could mean longtime fans are in for some major surprises.

After watching Gibbs finally find peace far away from Washington, one question now hangs over the new season:

What could possibly be important enough to pull Leroy Jethro Gibbs back into his past?

Fans won’t have to wait too much longer to begin finding out. NCIS: Origins Season 3 premieres Tuesday, October 6, 2026, with Mark Harmon back onscreen as Gibbs.