Adam Campbell will guest-star in a flashback episode that offers background on the team's chief medical examiner, TVGuide.com has learned.
"When we saw Adam, all we could think of was a young David McCallum," executive producer Gary Glasberg said in a statement. "We can't wait to introduce him as young Ducky and watch what he brings to this unusual role."
In the episode, which is scheduled to air in October, fans will learn about Ducky's past relationships and also learn why he has a penchant for bow ties.
Campbell previously played Cal Vandeusen on Harper's Island.
NCIS kicks of Season 12 Tuesday, Sept. 23 at 8/7c on CBS. Are you looking forward to meeting Young Ducky?
(Full disclosure: TVGuide.com is owned by CBS.)