When the late great Bob Newhart made a guest appearance in “NCIS” Season 8, he gave star Mark Harmon some advice. The veteran television actor’s sage wisdom wasn’t some artistic insight about the craft; it was something a lot more practical — and explicit.
Scott Williams, executive producer and writer of the CBS procedural, remembered the moment on a June 2026 episode of the “NCIS: Partners & Probies” podcast. It was 2011, and Newhart was chatting with Harmon during a lunch break. “He just said, in that very halting Bob Newhart sort of way, ‘So, uh, hey, Mark, can I give you some advice?'” Williams recalled. “He’s like, ‘Sure, Bob, what is it?’ He goes, ‘Ride this f**ker into the ground.'”
“Jobs don’t get better than this. You will miss this when it’s gone,” Williams overheard Newhart saying. “You’ve struck gold here.” Newhart had some experience being on a long-running hit series and the job security that comes with it. He led “The Bob Newhart Show” for six seasons and “Newhart” for eight in the ’70s and ’80s, respectively. When he appeared as Dr. Walter Magnus, Ducky’s predecessor as Chief Medical Examiner, “NCIS” had already been on the air as long as “Newhart” had. Still, he could sense that the military police procedural had the potential to keep going even longer and that Harmon would do well to stick around.
Harmon eventually left NCIS — but not for a while
Mark Harmon made his debut as Supervisory Special Agent Leroy Jethro Gibbs in a 2003 episode of “JAG” that served as a backdoor pilot for “NCIS.” He heeded Bob Newhart’s advice and continued to play Gibbs for a decade after their conversation. However, he did not quite ride it to the ground. Harmon left the show in season 19, which aired in 2021. In an appearance on “The Kelly Clarkson Show” two years later, Harmon said the grind and long hours started to wear on him. Speaking to Parade in 2024, he elaborated that the timing felt right for him to leave, especially since he was happy with the storyline the writers came up with to send his character off.
Harmon hasn’t completely left the “NCIS” world behind, though. He appears as an older version of Gibbs in “NCIS: Origins,” which he also executive produces. Scott Williams, who overheard Newhart’s advice to Harmon a decade and a half ago, is still holding strong. “When I heard that, I was like, ‘I am gonna do what Bob [said] — if they’ll have me, I’ll ride this f**ker as far as it’ll take me.'” Williams said on the “NCIS” podcast. “That inspired me. So, thanks, Bob Newhart, for sending that to me.”
