The star of FX's "American Horror Story" will play Duncan, a righteous FBI agent at the center of it.
When her family is swept into the conspiracy, she has to save her husband and children.
McDermott has previously starred on shows including "The Practice," "Big Shots" and "Dark Blue." He also appeared recently in the film "The Campaign." "Traitor" director Jeffrey Nachmanoff is writing, directing and executive producing the pilot, which is based on an Israeli format created by Alon Aranya, Omri Givon and Rotem Shamir.