There are only three characters still left who have been in NCIS since the beginning, those being Sean Murray, as Agent Timothy McGee, David McCallum, as Dr. Donald "Ducky" Mallard and Brian Dietzen, who plays the loveable Dr. Jimmy Palmer.
In an interview with Looper last year, Brian shared his thoughts on how the show might end, revealing he had no plans about leaving as he joked that the drama will conclude with its 40th season and Jimmy's retirement.
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When asked about what he thought a fitting ending would look like for the show, and for Jimmy, he said: "We're halfway there; Season 40 is when we'll stop. It's probably going to happen with Jimmy's retirement ... No, I have no idea.
"The cool part is, if you asked our writing staff or the other actors on this show, you wouldn't get any similar answers, because I don't think any of us are focusing on the ending of the show, considering what the ratings still are and how much fun we're still having."
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He continued: "In my estimation, I'm like, 'Let's keep concentrating on those great arcs.' If the time comes — because, as you said, everything will come to an end at some point — one of those arcs is going to lead us to the Promised Land and to the 'NCIS' ending. But if the ratings continue to be what they have been over the last year, I don't see that happening imminently."
Brian and Katrina Law as Jimmy and Jessica
The 44-year-old, who has starred on the show since 2004, also opened up about Mark Harmon's departure from the show.
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"On a personal note, I'm really thankful I got to work with Mark and call him a friend for that many years," he said. "I feel similarly about everybody I've worked with there. It's been a wonderful, wonderful place for 20 years.
"As people come into our set and people go, it feels like you're making new family members and you're making new friends all the time," he said. On not having Mark on the show, he described it as a "massive change".
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