Bob Newhart’s memorable visit to “NCIS” came with more than a guest role. According to longtime “NCIS” writer and executive producer Scott Williams, the late comedy legend also delivered a blunt piece of career advice to series star Mark Harmon during a Season 8 lunch break in 2011.
Williams shared the behind-the-scenes moment on a June 2026 episode of the “NCIS: Partners & Probies” podcast, recalling that Newhart approached Harmon in his familiar, halting style and asked if he could offer some guidance.
“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.’”
Newhart’s point, Williams said, was practical rather than philosophical. The veteran performer recognized that Harmon was sitting at the center of a rare television success — and he wanted him to appreciate it while it lasted.
“Jobs don’t get better than this. You will miss this when it’s gone,” Williams remembered overhearing Newhart tell Harmon. “You’ve struck gold here.”
Why Newhart’s advice carried weight
Newhart appeared on “NCIS” as Dr. Walter Magnus, Ducky’s predecessor as Chief Medical Examiner. By that time, the CBS procedural had already become a long-running network staple, and Newhart had personal experience with the kind of durability few TV actors ever get to enjoy.
He had led “The Bob Newhart Show” for six seasons and “Newhart” for eight seasons in the 1970s and 1980s, respectively. When he stepped into the “NCIS” universe in Season 8, the show had already been on the air as long as “Newhart” had been. Still, according to Williams’ account, Newhart seemed to sense that “NCIS” had the potential to continue even longer — and that Harmon would be wise to stay with it.
Harmon had first appeared as Supervisory Special Agent Leroy Jethro Gibbs in a 2003 episode of “JAG” that functioned as the backdoor pilot for “NCIS.” After Newhart’s 2011 advice, Harmon remained with the role for another decade.
Harmon stayed for years — but eventually stepped away
Harmon did not literally remain until the end of the franchise’s run. He left “NCIS” 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 had begun to take a toll. Speaking to Parade in 2024, he added that the timing felt right for his departure, particularly because he was satisfied with the storyline the writers created for Gibbs’ exit.
Even so, Harmon has not fully parted ways with the “NCIS” world. He appears as an older version of Gibbs in “NCIS: Origins,” a series he also executive produces.
Williams, meanwhile, said Newhart’s words resonated with him as well. The producer-writer, who overheard the exchange between Newhart and Harmon, said on the “NCIS” podcast that the advice influenced his own approach to staying with the series.
“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. “That inspired me. So, thanks, Bob Newhart, for sending that to me.”
The anecdote adds a revealing footnote to Newhart’s “NCIS” guest appearance: a seasoned television star recognizing another long-running hit in real time, and urging its lead to understand just how rare that kind of job can be.