Grey’s Anatomy alum T.R. Knight is returning to ABC and ABC Studios with a co-starring role in the untitled Meaghan Oppenheimer drama pilot, executive produced by Reese Witherspoon.

Written by Oppenheimer, the project follows the personal and professional life of Gemma, a ruthless divorce attorney in Dallas, which begins to unravel when her emotionally damaged, love-addicted sister resurfaces triggering self-destructive tendencies and exposing long-hidden family secrets.

Knight will play Mark, Gemma’s work nemesis who is competing with her for the same position. On the outside he’s a jolly and likable guy, but really he’s a calculated backstabber you don’t see coming.

Witherspoon executive produces alongside her producing partner Bruna Papandrea. Oppenheimer co-executive produces.

Knight is best known for his role as George O’Malley on Grey’s Anatomy. He was an original cast member on the ABC/ABC Studios medical drama, co-starring for the first five seasons and receiving an Emmy nomination.

Knight currently co-stars on the Hulu limited series 11.22.63 opposite James Franco. He was most recently on Broadway alongside Nathan Lane, Matthew Broderick and F. Murray Abraham in It’s Only a Play.

Knight is repped by  Thruline and Gersh.