As NCIS continues to air its 20th season in as many years, fans of the series are all missing the void left by the most iconic and important character from the show. At the conclusion of the previous season, Leroy Jethro Gibbs, the supervisory special agent played by Mark Harmon, bid farewell to the agency with a retirement to idyllic Alaska. The significance of this departure could not be understated: Harmon was one of two original regular cast members to complete 19 seasons and was the foundation of which the rest of the show was built around. Gibbs first appeared in the backdoor pilot for NCIS in 2003 as part of the JAG series and appeared in every season since.

Without Harmon's presence on the show, there has been a major shift in the series in order to fill the hole left by the senior agent that doesn't quite feel the same. Though the other characters continue to carry the torch, there's nonetheless a key ingredient missing that leaves this season feeling incomplete. Shows that have aired for so many years are destined to evolve, but sometimes those changes aren't for the better. So with such a drastic transformation for such a renowned and popular series, it begs the question: should the series have ended with Gibbs' departure?

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The Special Agents Were Always the Most Important Characters in 'NCIS'

NCIS and other crime procedurals have always been familiar with rotating and dynamic casts, but have always been reliant on a strong foundation by special core members. Given the episodic nature of the show, there are few recurring villains, which makes the antagonists of the series a far less memorable feature of the show. This puts an even greater burden on a strong cast of protagonists who help keep the series consistent and engaging over countless seasons. Gibbs was there from the beginning of the show and served as the grounding force to keep the series true to itself. He may not have been the only agent in NCIS, but he was the one that made this version of the series as memorable as it was. As the supervisory senior agent, he was the stoic and just leader of the other agents. He had a gruff, unreadable exterior atop a loyal and virtuous heart. It was Gibbs who spearheaded the rest of the team, pushing them to maximize their potential by leading by example on how to get the job done.

Following Harmon's exit, the only character to be credited in every episode of the series thus far is David McCallum as the personable doctor, Ducky. Though Ducky is a beloved member of the show, he was far removed from being one of its focal points. His role as a doctor kept him out of much of the action and investigating that thrilled the audience for much of each episode. That distance from the center of most plots meant that he would be unable to fill the void left by a character as involved as Gibbs. Whether he was on the ground and in the action or in the office smacking McGee on the head, Gibbs was ever-present the vast majority of interactions and storylines in every episode. As the roster of special agents around him changed over the seasons, Gibbs remained the core that they orbited around.

Jethro Gibbs Was the Leader Who Set the Tone of the Flagship Series

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Image via CBS

One of the defining features of the NCIS franchise is the variety of demeanors between its characters across different spin-off series. There are definitive tone setters for each version of NCIS, and for the original series, that job was handled by Jethro Gibbs. NCIS: LA is set in Los Angeles, so the team interrogates suspects in a boathouse, is based in an open-air Spanish-style building, and features a former LAPD liaison as one of their prominent characters. Compared to the original, their characters are more laid back and casual, like the Californians they're meant to be. This NCIS (which again, is the original) is based out of Washington D.C., a setting of paramount importance to the national safety these agents are meant to protect. Jethro Gibbs was the leader of that team for two decades and was the only character on the show who could truly embody everything that made the original NCIS unique to its spin-offs.

Gibbs' character was the textbook definition of an NCIS agent— or at least the perfect version of an agent for viewers to engage with. He was incredibly effective in his job but had little patience for bureaucratic nonsense. He was patient with his squad, but held them to high standards and showed little weakness. He had a complex, tragic past but forged ahead to make sure justice was attained. The layers and depths of Gibbs set the tone for the intricate, engaging narrative arcs and relationships. He was not only the leader of the team but the backbone of the entire series.

Where Does the 'NCIS' Franchise Go Next?

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Image via CBS/TVLine

Even though Gibbs was perhaps the most important member of the DC-based team, it's important to remember he wasn't the only one. It would be a disservice for characters like Timothy McGee (Sean Murray), who has been a series regular since its second season, to cut his storylines short. Fans might be left yearning to see where Nick Torres (Wilmer Valderrama) might advance in his career. However, even if NCIS ended with Gibbs' retirement, the precedent is still set for where fans can continue to see their characters.

Spin-offs of the series have proven that the world of NCIS expands far beyond just the DC base. With NCIS: LA coming to a close after its 14th season, there continue to be greater voids for NCIS fans. But the solution is not to force a show into something it could no longer be. Gibbs was the most irreplaceable, integral, and unforgettable character in NCIS and without him, it's a completely different show. The oft-grumpy but nonetheless reliable lead agent who served as the backbone of the ensemble has left a void that leaves the series feeling like a totally different show. Without Jethro Gibbs in the lead, it might be time to retire the original NCIS as well.