NCIS: Origins Is Bringing Young Ducky Back — While Mark Harmon’s Gibbs Faces a Mysterious Reunion of His Own

NCIS: Origins is preparing an episode built around two very different reunions — one viewers know is coming and another CBS is deliberately keeping mysterious.

The October 20 episode, titled “Return of the Mack,” will welcome Adam Campbell back as a younger Dr. Donald “Ducky” Mallard, allowing fans to see another important chapter in the friendship that eventually became one of NCIS‘ most beloved relationships.

But that’s only half of the story.

In the present-day timeline, Mark Harmon’s Gibbs will reunite with a familiar face from his past.

And for now, the identity of that person remains under wraps.

Young Ducky Joins Gibbs on a Murder Investigation

The episode’s 1992 storyline begins when a young Marine is discovered murdered on a beach, with suspicious markings covering his body.

Ducky joins the team to help investigate.

That puts Campbell’s young Ducky alongside Austin Stowell’s young Leroy Jethro Gibbs once again, continuing to fill in the history behind the friendship viewers knew for decades on the original NCIS.

Campbell is hardly a newcomer to the role.

He originally portrayed young Ducky during flashbacks on NCIS and later returned for the franchise’s landmark 500th episode.

“Return of the Mack” will mark his third appearance on NCIS: Origins.

Fans Will See Gibbs and Ducky Becoming the Duo They Remember

For showrunner David J. North, Campbell’s latest appearance isn’t simply another nostalgic cameo.

The episode is designed to show Gibbs and Ducky learning how to work together.

“We have a really fun episode with him and Gibbs where you’re really starting to see how they work together as a team for the first time,” North told TV Insider.

According to the showrunner, their evolving relationship begins revealing the foundations of the characters eventually portrayed by Mark Harmon and the late David McCallum.

North said viewers will finally be able to recognize how the younger men gradually became the Gibbs and Ducky audiences first encountered on the flagship series.

That gives Campbell’s return an added emotional significance following McCallum’s death in 2023.

Mark Harmon’s Gibbs Has His Own Reunion

The episode won’t remain entirely in 1992.

CBS has also teased a development in the present-day storyline:

“Gibbs reunites with a familiar face from the past.”

No identity has been revealed.

That mystery is particularly intriguing because Season 3 is already bringing people from Gibbs’ history back into his life.

Viewers know that Bobby Moynihan is appearing again as an older Woody, complete with aged-up makeup, in Episode 2.

North has also confirmed that Gibbs will cross paths with other familiar characters.

Exactly who is waiting for him in “Return of the Mack,” however, remains a secret.

Season 3 Is Digging Deeper Into Gibbs’ Past and Present

The dual storyline highlights one of the possibilities created by bringing Mark Harmon more directly into NCIS: Origins.

The series can continue exploring young Gibbs’ life through Austin Stowell while simultaneously revisiting those relationships decades later through Harmon.

“Return of the Mack” appears poised to take advantage of both timelines.

In 1992, viewers get another piece of the puzzle explaining how Gibbs and Ducky’s friendship became so enduring.

In the present, Gibbs comes face-to-face with somebody audiences may already know.

Adam Campbell’s Ducky is officially returning, but the episode’s biggest surprise may be the name CBS hasn’t revealed — the familiar face waiting to reunite with Mark Harmon’s Gibbs in the present day.