Throughout NCIS’ 23-season run, the CBS procedural has seen a lot of cast exits. Such changes are natural for a show that has been on the air for so long, but it never gets any easier to say goodbye, especially when someone has been on the show since the very beginning. Mark Harmon departed NCIS early in Season 19 in 2021, and Gibbs’ final episode was pretty emotional, given he finally found peace in Alaska. Unsurprisingly, filming the episode was incredibly emotional -- until Harmon hilariously broke the ice.By the time he left the show, Harmon was one of the only original NCIS cast members who'd been on the show since the very beginning. And I’m talking about the very beginning, with that two-part backdoor pilot on JAG. So it's understandable that his final episode would be emotional for the crew. Former NCIS writer/EP and NCIS: Origins co-creator David J. North appeared on the Partners & Probies podcast and spoke about filming Season 19, Episode 4, “Great Wide Open.” As part of that, he revealed how Harmon made sure the set was a bit lighter during the sad occasion:We’re shooting that last scene, and Gibbs tells McGee, ‘I don’t know what it is about this place, but I’m feeling a sense of peace that I haven’t felt since Shannon and Kelly died.’ That’s what we wrote. And we’re doing that scene, and I’m looking around, and everyone’s crying. Director Teri O’Hara crying, crew, I’m looking around, and we get to those lines, and Mark said, ‘I don’t know what it is about this place, but I haven’t felt this way since… what’s the name of my dead family?’ And everyone just burst out laughing. I love when actors are able to still have fun while filming an emotional scene. Given that Harmon was filming a very heartfelt moment between Gibbs and McGee in which the former talked about his late wife and daughter, you’d think that even he would be in his feelings. But it’s great that he was still able to make light of everything, given the circumstances, and turn the crew's sobs into laughs. Of course, not everything was funny behind the scenes at the time.When Harmon exited NCIS, producers felt it would be the death knell for the series, and creative decisions had to be made quickly. Cast member Gary Cole was baffled by Harmon’s exit, having previously revealed that there was no “definite plan” when Harmon left, and he felt that the entire thing was rushed. Still, it was fitting that Gibbs retired to Alaska and was able to find happiness after everything he'd been through.Luckily, even with Harmon gone, though, NCIS is still going strong. The series is about to enter its 24th season next month, which is wild to think about. Additionally, Harmon is going to be appearing as Gibbs in all 10 episodes of NCIS: Origins’ upcoming third season. He serves as executive producer and narrator and has appeared on-screen in a few episodes already. Yet, with him appearing in all episodes of the new season, we're seeing his most substantial role in the franchise in years.Of course, it's unknown if Mark Harmon will ever return to the Mothership and, at present, his exit remains one of the more emotional points in the franchise's history. Fans can rewatch his final installment and all of his episodes with a Paramount+ subscription. New seasons of NCIS and NCIS: Origins premiere on Tuesday, October 6, on CBS.