The cast of one of the longest running TV shows, "NCIS" has come and go. One of the most controversial exits is that of Michael Weatherly, but aside from that, fans are also worried about Mark Harmon's decision to leave the TV series.

There have been reports about Harmon's plan to quit "NCIS." Harmon plays the role of Agent Leroy Jethro Gibbs, which is one of the significant characters of the CBS drama. No doubt, his departure will leave an empty space in the series. However, the writers are already competent in handling exits as well as the arrival of new characters.

Harmon's decision to leave the series is said to be due to health reasons. Fans noticed Harmon's weight loss, and many expressed their concern that he looks pale. However, the actor had a different tone during an interview with TV Insider.

He said that he is done with the show once he sees the writers with heads down while walking into the writer's rooms. According to him, this would mean that they have done it all. However, he thinks it's not going to end yet because there is still a "feeling of creativity and sense of reinvention" on the set.

"NCIS" season 15 also welcomed new cast member Maria Bello who plays the role of a forensic psychologist Jacqueline Sloane. Her back story was featured in episode 9 titled, "Ready or Not" which aired on Nov. 21. In the same episode, Tim McGee (Sean Murray) and Delilah Fielding (Margo Harshman) welcomed their first baby.

There will be a two-week hiatus for the series since the next episode will air on Dec. 12 titled "Double Down." This episode will feature guest star James Morrison who plays the role of U.S. Senator John Phillips. Torres and Sloane will be protecting Phillips in Afghanistan where he is spending his holiday.

CarterMatt reports that the senator needs to cut his vacation short since his son is in the ICU. With this, Gibbs and the rest of the team will investigate the case. They will look into the cause of the life-threatening injuries of the senator's son.

"NCIS" season 15 episode 10 will air on Tuesday, Dec. 12, at 8 p.m. EST on CBS.