Have you only just picked your jaw up off the floor after The Diplomat’s shocking Season 3 finale? Well, prepare for another round of political drama — because Kate Wyler’s (Keri Russell) diplomatic assignment has been extended. The Diplomat Season 4 was announced earlier this year, and series creator Debora Cahn promises even more surprises ahead for Kate, her husband Hal Wyler (Rufus Sewell), and the cutthroat political players who surround them. 

“I’m so excited about Season 4,” Cahn, the showrunner and executive producer, tells Tudum. “It’s going to be a lot of fun. We get to the end of a season and I always think, ‘Well, there’s no way that we can do this again.’ And then we dig back into it, and it’s like, ‘Oh my God, we have to keep going.’ ”   

When The Diplomat Season 4 begins production this fall, The West Wing alums Allison Janney and Bradley Whitford will be busier than ever. The duo — who portray President Grace Penn and first husband Todd Penn — have been promoted to series regulars. In Season 3, we see Grace and Todd explore how the White House (and the Wylers) affect the Penns’ marriage. 

“Working with Allison and Brad, watching them together again, and the off-the-charts foursome that is them with Keri and Rufus … It’s an insane bag of candy,” says Cahn. “Our expectations were high, and it blew right past them.”

Executive producer Janice Williams previously told Tudum that “Bradley was the perfect addition to what is already a dream cast.” 

Additionally, Nana Mensah, who plays White House Chief of Staff Billie Appiah, has also been promoted to series regular for the show’s fourth season. 

As you await the return of The Diplomat, you can still dig into the twists and turns of Season 3. The eight-episode season follows Ambassador Kate Wyler as she lives the particular nightmare that is getting what you want. The old president (Michael McKean) is dead. Grace Penn is the new POTUS. And she has her eye on the Wylers. As Kate steps into a role she never wanted, with a freedom she never expected, she finds herself with a whole new set of expectations and obstacles. The Season 3 finale suggests The Diplomat will weather more complications than ever in Season 4. 

“[Fans] should be worried. There’s plenty to worry about,” says Cahn. “It can be pretty chilling when you see who takes power and get the sense that they may be horrifically misusing it.”

But Russell adds that the “unraveling will be fun.” And Sewell agrees. “Whether Kate and Hal are warring, whether they're together, whether there’s other people, it's fun for us, whatever’s happening,” he says.

Stream all three seasons of The Diplomat now. And keep coming back to Tudum for more briefings from the Penn White House. 

Additional reporting by Ruth Kinane. 

Watch Keri Russell and Rufus Sewell Discuss The Diplomat Season 3