Throughout NCIS’ 23-season run, the CBS procedural has had a lot of guest stars gracing the halls of HQ. A lot of them were actors who were not quite stars yet, such as Zac Efron and Glen Powell, while others were already pretty big names, including Mark Harmon’s Freaky Friday co-star Jamie Lee Curtis. Bob Newhart is also on this impressive list, but he did more than just guest star. He gave Mark Harmon an F-bomb-laced piece of advice, too.
The late great Bob Newhart guest starred in Season 8, Episode 12, “Recruited,” back in 2011. He portrayed Dr. Walter Magnus, a retired chief medical examiner who trained and mentored Ducky. He was only in one episode, but he left a mark on the show and is one of the greatest NCIS guest stars. He also made quite the impact behind the scenes too, as executive producer Scott Williams recalled the advice he gave Mark Harmon on the NCIS: Partners & Probies podcast:
