Keri Russell 'Doesn't Remember Any Other Relationships' Other Than Matthew Rhys (Exclusive)

In The diplomatKeri Russell plays a US ambassador married to a diplomat. While that may sound glamorous, Kate Wyler (Russell) and her husband Hal (Rufus Sewell) don't often embody a perfect marriage.

Russell, 48, describes the Wylers' relationship as “complex.”

“This season feels kind of heartbreaking,” she tells PEOPLE. “It feels very adult and true to the reality of knowing someone for so long. But when it comes to Kate and Hal, you can't have one without the other. It’s so entangled that it’s part of her appeal.”

Russell has practical experience working with a long-term partner, Matthew Rhys, who she began dating in 2014, when they first started dating The Americans. She and Rhys, 49, welcomed son Sam in May 2016.

“It can be a really nice shortcut because they know what work means to you, but it can also feel like a lot sometimes,” Russell says of having a significant other who works in the same field. “But it can be nice to have someone doing something completely different so that there is something of a break. But I’ve been with Matthew for so long that I can’t remember any other relationships.”

Season 2 of The diplomat The plot begins with the aftermath of an explosion in London, in which Hal and some of Kate's colleagues were injured. “I think that was just as surprising to us when we read it,” Russell says of the shocking conclusion to the first season. “We had no idea where it was going.”

In Season 2, when Kate realizes that the explosion has come from within the British government, she begins to question “who she can trust and who she can't,” says Russell.

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Kate continues to consider whether she will run for Vice President of the United States. “All of that trickles down, but the introduction of (Allison) Janney’s character really complicates the mix,” says Russell.

Janney, 64, joins the second season as Grace Penn's vice president. Russell told PEOPLE at PaleyFest 2024 that she “was a little nervous” about Janney wanting to participate The diplomat because “she’s great and so good.”

“But she’s everything you expect her to be,” Russell said. “She’s kind and funny and smart and cool.”

The bliss Alum says The diplomat Season 2 begins a few days before the first female vice president of the United States runs for the highest office in the land – an “incredibly eerie” coincidence.

“We did this a year and a half ago, before all of this,” says the actress. “It just so happens that it worked very much in our favor.”

Season 2 will consist of six episodes, compared to eight episodes of the first season – but The diplomat was already renewed for a third season by Netflix earlier this month. The diplomat Creator, showrunner and executive producer Debora Cahn told Tudum that in Season 3, Kate will experience “the special nightmare that is getting what you want.”

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The diplomat Season two premieres Thursday, October 31, on Netflix.