'Homeland' Season 3 Casting: Amy Morton, Tracy Letts, Lawrence Clayton And More Join Showtime Drama

"Homeland" Season 3 is adding to its cast, with stars such as Joanna Merlin, Nazanin Boniadi, Amy Morton, Lawrence Clayton and Tracy Letts joining the Emmy-winning drama, Showtime announced today.

Amy Morton will play recurring character Erin Kimball, the CIA attorney appointed to Carrie Mathison (Claire Danes) following the events of Season 2. "Law & Order: SVU" star Joanna Merlin will appear as Grandma Lois, Jessica Brody’s (Morena Baccarin) mother.

Nazanin Boniadi will appear as Fara, a capable analyst despite her young appearance, while Gary Wilmes will play Dr. Richardson, a psychiatrist helping Dana Brody (Morgan Saylor) cope with recent events. Sam Underwood will play Leo, a new friend of Dana’s with a troubled past.

In the wake of the terror attack on U.S. soil, the government’s investigation deepens, and according to Showtime, those asking for answers include Tracy Letts ("Prison Break") as Senator Andrew Lockhart, the powerful, authoritative and commanding Committee Chairman; Broadway veteran Lawrence Clayton as Admiral Jim Pennington, the President’s National Security Advisor, and Pedro Pascal as Majority Counsel David Portillo, a member of the Senate Select Committee on Intelligence.

As the cable network previously announced, "Homeland" Season 3 opens during the aftermath of the terrorist attack that capped Season 2 and prompted Nicholas Brody (Damian Lewis) to flee the country -- with the help of Carrie Mathison. The new season also finds Carrie and Saul (Mandy Patinkin) begin to rebuild their personal and professional lives in the middle of a media firestorm about the terrorist attack and search for Brody.

Rupert Friend and Jackson Pace will also return for the 12-episode Season 3.

"Homeland" Season 3 premieres Sunday, Sept. 29 at 9 p.m. ET.

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