Adam Campbell's "NCIS" character, who has appeared on the mothership in flashbacks as the young version of David McCallum's Ducky, is sent to work with our "Origins" team to see if they need an in-house medical examiner. But the crew at Pendleton is skeptical of his true motives.

“He always had a way of knowing who I was meant to be.” So says Mark Harmon in the emotional voiceover that caps off the NCIS: Origins serving as a tribute to the late David McCallum, with Adam Campbell reprising his role as the young Ducky.

David J. North: “It's not like any piece of wardrobe. It's definitely cherished, but they shoot the original NCIS up in Valencia, California, and we reached out to them and asked for the hat, and that's how that's how we had it. But yeah, it was a really cool thing and Adam was so excited.”

"NCIS: Origins" honors David McCallum in a tribute episode Oct. 28 featuring young "Ducky" Mallard's return. USA TODAY gets an exclusive sneak peek.

Origins would deliver its own tribute to fan-favorite Donald “Ducky” Mallard, it was hard to know what to expect from this venture or whether Adam Campbell could reprise the role in a way that aligned with this spinoff.

Gibbs gets a visitor at Camp Pendleton from DC Headquarters in a new NCIS: Origins Season 2, Episode 3 sneak peek. See the very special reunion here.