House of Cards' Corey Stoll and In Treatment's Laila Robins have joined the fourth season of Homeland, Showtime announced today.

A series regular, Robins will play Martha Boyd, the "professional and put together" U.S. ambassador to Pakistan, while Stoll will guest star as Sandy Bachman, the CIA chief of station in Pakistan.

Following the status quo-changing end of Season 3, which saw Brody (Damian) executed and Carrie Mathison (Claire Danes) pregnant and starting a new phase of her career, the fourth season finds her "assigned to one of the most volatile and dangerous CIA stations in the Middle East, where she is back on the front lines in the war on terror."

Mandy Patinkin, Rupert Friend and Nazanin Boniadi also return for Season 4, which begins production later this month in Cape Town, South Africa.