NCIS Season 21's Big Surprise Will Affect McGee In A Big Way, Says Sean Murray

Contains spoilers for "NCIS" Season 21, Episode 5 — "The Plan" 

"NCIS" might not be the first series one thinks of when it comes to huge plot twists, but Season 21 is set to pull quite the shocker on Timothy McGee (Sean Murray). In "The Plan," when his wife Delilah (Margo Harshman) talks him into taking a DNA test to facilitate her interest in genealogy, McGee is stunned to learn that he has an unknown relative. McGee doesn't want to open this particular Pandora's box in the first place, but when he does, he is shaken up, yet driven to pursue the matter.

"That freaks him out pretty good. But he goes down that rabbit hole," Sean Murray told TV Insider, admitting that he was also surprised by the plot twist. There's no word as to who McGee's possible relative might be. Still, Murray seems excited to play out the ripple effect that this might have on his character; he seems to be quite proud of his growth in general over the years and remains quite resistant to the idea of stagnation. "I remember saying early on to our writers and showrunners that McGee cannot be baby Maggie Simpson. He cannot revert to the same character every week without growing. We can't have that," he said, also noting that he and the writing team were happily on the same page.

Thus, McGee has grown and changed exponentially with time. Said exponential growth includes his relationship with another relative –  his sister, Sarah (Troian Bellisario). While audiences haven't seen Sarah in a while,  Murray admitted that he spent some time with Bellisario recently — and they both had the same question about the character's future.

Sean Murray told TV Insider that he has no idea if viewers will get to see Sarah McGee again soon, but seems hopeful it will happen. "It's really funny that you mentioned that because while I don't know whether that will happen, I did have lunch with Troian, my stepsister, a couple days ago, and we were talking about some of that stuff. Who knows what may happen? We don't know." In what is definitely one of the many fascinating facts about Sean Murray, his mother, Vivienne, married Bellisario's father, Donald P. Bellisario, in 1998.

The 21st season of "NCIS" has made a huge format change to the way it tells stories, and that choice to center the abbreviated season around character-based storylines will also affect McGee. Murray previewed two stories for Timothy and Delilah that will revolve around their home lives, including the couple's hopes to refurbish their apartment, which once belonged to Tony DiNozzo (Michael Weatherly). Delilah also involves McGee's colleagues in an online poll designed to coax her husband into shaving off his goatee — a concept he's not into. Audiences will find out how these gambits play out as 2023's most-watched prime-time TV show returns to the airwaves on March 25.