It's the end of the road for Mark Harmon on NCIS. Since 2003, Harmon had been starring in the popular CBS series as Supervisory Special Agent Leroy Jethro Gibbs. After 18 seasons, there were reports that Harmon was looking to exit the series. He ended up signing back on for season 19, reportedly after he learned that the show probably wouldn't be renewed if Harmon didn't return.

At the time of the renewal, it was reported that Mark Harmon may only be returning for a handful of episodes. That was proven to be the case as the fourth episode of season 19 officially wrote Gibbs out of the series. The moment came when (SPOILER ALERT) Gibbs decided not to take back his badge after narrowly surviving the boat explosion in season 18. After tracking down a hitman in Alaska with Special Agent Timothy McGee (Sean Murray), Gibbs declared that he was going to stay put.

"I'm not going back, Tim... I'm not going back home," Gibbs said, casting a fishing line into a lake. He explains how he now feels a "sense of peace" being in the middle of nowhere, and he's "not ready to let it go" by leaving. Before McGee departs, Gibbs tells him, "I could not have hoped for anyone better to have watched my back for the past 18 years than you, Tim." The two then hug in an emotional scene, and while it may not be the last time we'll ever see them together, it's not going to happen for a while, or ever in the same capacity again.

In a statement, NCIS showrunner Steve Binder addressed Mark Harmon's exit and said, "As an executive producer and dear friend, Mark continues to be an integral part of the fabric of the show. Our north star has always been staying true to our characters, and that truth has always guided the stories we tell and where those characters go. So regarding the future of Gibbs, as long-time fans of the show may have noticed over the years... never count Leroy Jethro Gibbs out."

This doesn't necessarily mean we'll never see Gibbs again on NCIS. Prior to the episode's airing, CBS Entertainment President Kelly Kahl also suggested that Harmon's presence will always still be a part of the series in some way. There's no indication as to when he might physically see Harmon back on the show for an onscreen appearance, but Kahl did tell Deadline last month, "Mark's always been part of the show, Mark's always going to be part of the show. In terms of his on-air appearances, we're just going to have to see how it plays out going forward."

This year, the spinoff NCIS: New Orleans wrapped its run after seven seasons, but the NCIS franchise continues to go strong. The separate spinoff NCIS: Los Angeles just recently premiered its 13th season on CBS. Last month, the brand new spinoff series NCIS: Hawai'i premiered, and this week, it was given a full season order by CBS, which is a good sign for the new show moving forward. Even so, many longtime fans are partial to the original NCIS, which will now be moving on without Mark Harmon in the lead. This news comes from TVLine.