Mark Harmon is stepping back into the role of Leroy Jethro Gibbs after his exit from NCIS. CBS announced on Tuesday, October 28, that Harmon, 74, will make a special guest appearance during the first crossover event between NCIS and NCIS: Origins. The two shows intersect on Tuesday, November 11, with younger Gibbs (Austin Stowell) and the team investigating the small-town death of a naval officer in the '90s. The case is then "unexpectedly reopened in the present day on NCIS," according to the official synopsis, which teased how "the decades-spanning mystery finds the air order for the series switching for one night only," with NCIS: Origins moving to the 8 p.m. ET slot while NCIS will follow at 9 p.m. ET. "Four years ago, Gibbs disappeared to Alaska to live a life of solitude," executive producers David J. North and Gina Lucita Monreal said in a statement. "We know how much fans have missed seeing Mark and have wondered what Gibbs is up to today. Well, on November 11, we're so excited to announce that Mark Harmon will return as Leroy Jethro Gibbs in the Origins hour of the NCIS crossover event. We don't want to give too much away, but let's just say Gibbs is no longer alone." Every Star Who's Left 'NCIS': Where Are They Now? Harmon also weighed in on his decision to return, saying, "I'm very proud of the storytelling that David and Gina are doing on Origins. They continue to push boundaries and dive deeper into the characters' backstories. They came to me with an idea for Gibbs that I liked, and it seemed like a good time to check in with him. I hope fans enjoy it." In the first look at Harmon's return, his present-day version of Gibbs is seen pouring himself a drink. This marks a rare return for Harmon, who has remained an executive producer of both shows and is a narrator on the NCIS prequel but hasn't played Gibbs on screen beyond the newer show's 2024 pilot. Robert Voets;Sonja Flemming/CBS(2) Harmon made his NCIS debut as Gibbs in 2003 and played the lead role for 18 years. His final appearance aired in late 2021, and Harmon moved on to work on the prequel alongside his eldest son, Sean. "What has always drawn me here is the character I play and to keep it fresh and to keep it challenging," Harmon said about his exit in an August 2022 interview featured in the season 19 DVD release. "Plot-wise, this character has taken the path that it did. I'm not retired. The character is living in Alaska as far as I know." After Harmon made the move behind the scenes, Stowell, 40, praised the actor for his help in creating a younger version of Gibbs. "It's a daunting task to recreate Gibbs and to go back and try to tell this story while being respectful to the fans and to the story line of the original show," Stowell exclusively told Us Weekly in November 2024. "We want to do our best job as actors, as artists, as writers and storytellers. While there could be a lot of pressure, Mark Harmon makes us feel so comfortable and he makes us feel justified in our decisions." Stowell revealed that it didn't take long for Harmon to share his opinion on his performance. "He gave it to me right away in the room," Stowell quipped. "He was vocal about - maybe not what to do - but certainly [he was] guiding me more in terms of posture and mindset, things that I've learned to inhabit all the more over time." 'NCIS' Stars Who've Confirmed They Would - Or Wouldn't - Return to Show Harmon, however, has "never given" Stowell any notes on his acting. "He leads by example. He's a guy who I've learned a lot more about being a human being than being Gibbs," Stowell continued. "He's been so welcoming - not just to me and not just to the rest of the cast, but the whole crew. He's really such a wonderful leader for us because he makes everybody feel so comfortable." Monreal and North also spoke to Us about Harmon's reaction to the prequel. "He is always really available to us, which has just been such a gift throughout this whole process. He was there by our sides during casting and he comes to table reads," Monreal shared with Us in April. "I get a wonderful opportunity to be there with him when he records the voiceover, and he has made himself available to all the actors. They adore him. He's always open for questions and conversations. So we've been so lucky that he's been so present and supportive along the way." North opened up about getting Harmon's stamp of approval on this chapter of Gibbs' journey, saying, "I'll be honest, he's a tough guy to win over. But because he has a high bar of what he wants to accomplish - Gina and I are fortunate enough to have worked hard and done a lot of work for him, and we have won him over up until this point and we adore him." He added: "I think the feeling is mutual, and this has just been the greatest project. I know he says that for him and certainly for me. He's always a call away and he absolutely gives input that affects what you see on this show. But ultimately he said, 'You're the team I want