The latest "NCIS" season 12 sneak peek has already been released. And seeing the promo clip, it looks like it's going to be a very emotional winter finale episode. 

Episode 10 is titled "House Rules," and the official synopsis reads: "The NCIS team will end up, consulting with three cyber-terrorists they imprisoned after a city-wide Internet shutdown the week before Christmas. Also, McGee is going to reflect on the case and Gibbs' infamous rules as he pens a heartfelt letter to his father." 

In the promo, it is seen that character Tim McGee, played by Sean Murray, gets emotional while saying his thanks. 

He says, "I just want to thank you, for everything." 

That single line has gotten fans worried about Murray leaving the show because it seems like a goodbye message from his character. 

Could he really be leaving? While there is no news confirming that he is or isn't, Carter Matt says that it is unlikely to happen. The site says that Murray is still under contract and it is really depressing to let go of a series regular on a Christmas episode. 

So, why is McGee so emotional during the episode? Carter Matt speculates that he could be writing a letter to his dad. In the previous seasons, it was revealed that his father has cancer. His letter may just be the only way he can finally tell his dad that he loves him and that he is thankful, before his father passes away. 

Gibbs (Mark Harmon) somehow relates to McGee's emotional moment as the former has been like a father figure to him. So maybe, being under Gibbs' rules and guidance, McGee has realized a couple of things that he needs to say to his father. 

"House Rules" is written by Christopher J. Waild and directed by Terrence O'Hara. It will air on Dec. 16 at 7 p.m. on CBS.