Warning: Spoilers for the NCIS season 21 finale

Summary

• McGee & Palmer are essential to NCIS as the only remaining characters from season 1, providing irreplaceable depth and history to the show.
• McGee's evolution from guest star to Senior Field Agent and potential NCIS Director showcases strong character development over 21 years.
• Palmer's journey from assistant to Chief Medical Examiner highlights gradual growth and potential personal developments in the season.

Timothy McGee (Sean Murray) and Jimmy Palmer (Brian Dietzen) are invaluable mainstay cast of NCIS characters at that time, consisting of Jethro Gibbs (Mark Harmon), Tony DiNozzo (Michael Weatherly), Dr. Mallard (David McCallum), Abby Sciuto (Pauley Perrette), and Kate Todd (Sasha Alexander). While they were the regular cast at the time, other season 1 characters like Jimmy and McGee are just as memorable as the original core MCRT , especially since their legacy has endured on the flagship series.

When the show first premiered in 2003, McGee and Palmer were just getting their start at NCIS, making only sporadic appearances. Their roles on NCIS could have amounted to nothing more than a one-off feature for the stars. Instead, they culminated in careers that have spanned two decades for both actors. Astonishingly, both McGee and Jimmy will re the cast in NCIS season 22 to continue to tell their stories.

Timothy McGee & Dr. Jimmy Palmer Are Invaluable Because They Are The Only Remaining Characters From NCIS Season 1

All The Other Season 1 Cast Have Departed The Series

Timothy McGee and Dr. Jimmy Palmer are invaluable to the current cast of NCIS because they are the only Major Case Response Team who have been with the show since NCIS season 1. Caitlin Todd's shock season 2 NCIS death marked the first time that a main character left the show. Although the other characters would stay on the show for many years, most notably Jethro Gibbs and Dr. Mallard who stayed on the show for 19 and 21 years respectively, all the other original cast have long since departed NCIS.

While Jimmy and McGee weren't mainstays, they were featured on the show throughout its first season. It would be standard for most TV programs to have an actor stay with the show for its entirety, but in the case of NCIS, the accomplishment is significant, considering that the actors have been with the show for two decades. While their occupations could be filled by the show's rotating cast of characters, the legacy the actors have as season 1 characters is impossible to replace. The expansion of their story needs to happen in NCIS season 22, and their current trajectory certainly allows for it.

How Sean Murray's Timothy McGee Has Evolved On NCIS

His Role Evolved From Guest Star To A 21-Year Legacy

Timothy McGee is introduced to the franchise in NCIS season 1, episode 7, "Sub Rosa." McGee is an NCIS agent assigned to the Norfolk Naval Base, and he assists the team on their case with his technical skills. After his first appearance on the show, an editing mistake turned Sean Murray into a regular on the show when he appeared opposite Tony DiNozzo again in episode 11, "Eye Spy," to provide the team with another technical assist. After Murray appeared again in episode 11, his character appeared regularly at the end of the show's first season.

Agent McGee was featured in episodes 18 through 23 to assist Gibbs' team. Most notably, McGee offered his technical skills to speed up the identification of season 1 antagonist Ari Haswari (Rudolf Martin). McGee crafted a program that was able to more quickly locate Ari using facial recognition intelligence. Not only did McGee provide major intel that led them to Ari, but he also earned Gibbs' approval and ultimately earned his role on the MCRT. After helping the team solve the case in the season 2 opener "See No Evil," McGee officially ed the MCRT, being promoted to a full-time agent.

As his colleagues continued to depart the team for other pursuits, McGee's role in the MCRT steadily progressed. When NCIS, McGee was promoted to Senior Field Agent. When Gibbs departed the team after his journey led him to Alaska in NCIS season 19, McGee became second-in-command behind the team's new lead, NCIS Supervisory Special Agent Alden Parker (Gary Cole). Then, in seasons 20 and 21, McGee has moments where he steps in as temporary NCIS Director, signaling that his character's evolution could lead to the ultimate NCIS rank in time.

How Jimmy Palmer's Medical Examiner Role Has Evolved

Brian Dietzen's Role Has Evolved Far Beyond Jimmy Palmer

Now serving as the Chief Medical Examiner for the Major Case Response Team, Dr. James "Jimmy" Palmer originally started out as the Assistant Medical Examiner to Dr. Mallard. Jimmy's appearance on the show was originally temporary. He began filling in for Ducky's former assistant Gerald Jackson (Pancho Demmings) after he suffered a gunshot wound to his shoulder in season 1, episode 16, "Bête Noire," which was one of the show's best episodes across NCIS' 21 seasons. His debut appearance on the show was NCIS season 1, episode 22, "Split Decision."

Jimmy Palmer's role has experienced a slow but steady evolution. While he also ed the flagship series in season 1, it took longer for Palmer's character to become a mainstay on the show. His character became more consistent when Jimmy took over as Ducky's new assistant following Gerald's eventual resignation. Brian Dietzen became a regular cast member on the show at the beginning of season 10. In season 14, episode 13, "Keep Going," Jimmy reveals that, after multiple attempts, he ed the Medical Examiners exams and is officially qualified to be the team's Medical Examiner.

After years as Ducky's assistant, Jimmy took the ultimate step in his journey when he became the Chief Medical Examiner for the NCIS Major Case Response Team. The former medical examiner retired in season 15, which was why Dietzen's guest appearance leading him to show writing. Dietzen has writing credits on three episodes of NCIS, including season 21, episode 2, "The Stories We Leave Behind," which paid tribute to his predecessor.

How NCIS Season 21 Set Up The Character's Futures In NCIS Season 22

The Characters Both Bared Their Personal Lives In NCIS Season 21

NCIS season 21 was memorable for both characters. Timothy McGee filled in as temporary NCIS director when Director Leon Vance (Rocky Carroll) was shot in the 1000th episode of NCIS. He was serious and capable of the role. The season shared bits of McGee's personal life, like a feud with his wife Delilah Fielding-McGee (Margo Harshman) over his mustache, and drama surrounding a kitchen renovation in the couple's home. While the insights into McGee's life were charming on some level, the writers could opt to develop his relationship beyond the simple bickering it fell into in season 21.

Likewise, Palmer's life got the spotlight in the NCIS season 21 finale. It was a shocking twist when Director Vance reached out to Jessica Knight (Katrina Law) about a promotion to Chief REACT Training Officer. The decision will surely bring huge changes for Jimmy's character in NCIS season 22, possibly including an under-the-radar solution to Jessica Knight's NCIS departure where Jimmy could follow Jess to Camp Pendleton for her new gig. The season could also see Jimmy's character develop to not please other people so much, as hinted at in the finale.

In the season, the characters have unlimited development potential. McGee could advance to NCIS director. While Jimmy is already near the top of his career, his character could experience personal development that sees his character evolve yet again, 22 years after he ed the show. What's certain is that NCIS has continued to develop the characters and that McGee and Jimmy are in a unique position to evolve the franchise with the depth that could come from their characters if written well in the coming season. As season 1 characters, what they bring to NCIS is irreplaceable.