<i>The Diplomat</i>’s Season 3 Finale Is a Shock for Kate—and the Rest of the Globe

Spoilers below.

For Kate Wyler, Keri Russell’s central character on The Diplomat, the personal is always entangled with the professional. She’s a career diplomat who is married to Hal Wyler (Rufus Sewell), another long-term ambassador who she met on the job. That is, until he’s called up to be the Vice President in the season 3 premiere—a job she was also in line for.

Their marital issues are intertwined with the political drama of the Netflix thriller, especially as Hal and Kate navigate how to handle one of their careers usurping the other. After Hal’s promotion, Kate, the ambassador to the UK, retains her position while also gaining another, less flattering title (in her opinion): Second Lady. Feeling overlooked, Kate opts to be the Second Lady in name only, effectively ending the intimacy in their marriage again, though they remain a united front publicly.

But season 3 is about much more than the continued, slow dissolution of the Wyler partnership; It also contends with the icy relationship between the U.S. and the UK, spurred by the reveal of American involvement with the attack on the British aircraft in season 1. The finale “Schrodinger’s Wife” brings Kate’s personal and professional lives into sharp focus, taking place in England over a private summit between the former-VP-now-President Grace Penn (Allison Janney) and the UK’s Prime Minister Nicol Trowbridge (Rory Kinnear), with their significant others in tow.

The summit is supposed to act as an apology for the aircraft attack, which was orchestrated by Penn but pinned on her now-deceased predecessor, President Rayburn. Even more pressing is the discovery of a Russian submarine off the coast of the UK, which British agent Callum Ellis (Aidan Turner)—who is sleeping with Kate—tells Kate also holds a deadly weapon nicknamed The Poseidon. Penn acts on it immediately, but given the standing between the two countries, Prime Minister Trowbridge opts to not believe President Penn’s claims, calling it a “fictional tool.” Penn pleads with him to not give China access to the tool and offers American help, which Trowbridge scoffs at before leaving the room.

With Kate as one of the remaining trustworthy bridges to the UK government, she meets with the Foreign Secretary Dennison (David Gyasi) to find a path forward. He suggests that Hal try to reason with the Prime Minister, as he might better receive the news if it came from a man. Kate goes to her next trustworthy source, Callum, and asks him if all of this is a move by the UK to get something out of Penn’s government. She encourages him to reveal his intelligence and his source, which he vehemently declines, knowing that going to the Americans with information instead of the Prime Minister would be the end of his diplomatic career. Kate’s insistence on his cooperation leads him to believe that this is Hal’s way of getting him out of the picture, and he’s not willing to stand down so easily.

While all of this negotiating is occurring in the background, the government officials and their significant others attend a dinner hosted by the Prime Minister. Things are tense, as the conversation is largely led by President Penn’s husband, Todd (Bradley Whitford), a former biologist who is salty that his career is both “alive and dead” due to his wife’s pursuits. He posits that all of the spouses, especially Kate, are in this same position—a nod to the episode’s title.

During the dinner, Kate is summoned by Callum, who concedes and agrees to talk to the Prime Minister about what he knows. Kate promises protection in return. But when she relays the good news to Hal, he shuts it down. When they finally talk in private later, Hal expresses both jealousy and his desire for her happiness, suggesting that her idea is throwing Callum to the wolves while Hal is trying to salvage it for her. Ever the problem-solver, she comes up with another solution: They’ll send an American submarine to take photos of the Russian sub and its weapon to prove its existence to Trowbridge. President Penn is initially skeptical of the idea, but after Kate leaves their meeting, Hal convinces Penn that “there’s a way to make this something she likes,” suggesting the president and VP know something Kate doesn’t.

While Hal and Penn are discussing their secret plan, Kate runs into Dennison, enjoying a drink in solitude. The two seemingly haven’t spoken since their failed attempt at a hookup earlier in the season, and Kate has been walking on eggshells ever since he showed up this weekend with a wife in tow. The old friends finally get a chance to talk, and Dennison reveals that he and his wife, Thema (The Pitt’s Tracy Ifeachor), were involved before he got married. Dennison is moved by Kate’s own struggles with her marriage and how she tried her best to make things work. When Kate counters with her outsider’s view of his “perfect” marriage, he reveals that his first wife killed herself, shattering that illusion for them all. Given their history, Dennison intimately knows Kate and Hal’s issues and encourages her to be patient with Hal. Kate takes those words to heart immediately, and when Callum comes up to her room, she first relieves him of his martyrdom by telling him about the photo plan and then stops him mid-kiss to make an excuse about having to go back to work, though she’s not involved with the operation.

Prime Minister Trowbridge is presented with photographs of the submarine the next day, but his distrust in the Americans remains. He believes these could be doctored, and Dennison offers to have their intelligence corroborate the images. More than anything, he believes that he’s being deceived once again and that the United States is after the weapon for themselves, which prompts Hal to utilize Kate’s close relationship with Trowbridge. He directs her to “Runit Dome,” referencing a previous operation in which the countries cooperated to bury a similar genocidal weapon in concrete at the bottom of the ocean. Trowbridge seems satisfied with this neutral option and shakes Penn’s hand to acknowledge the agreement.

As all of these negotiations are taking place, members of the White House staff are becoming increasingly disillusioned—namely, Stuart (Ato Essandoh), the deputy chief of mission of the US embassy in London. First, he mentions his dissatisfaction about the Rayburn allegation to the White House chief of staff Billie (Nana Mensah), noting that he doesn’t blame Trowbridge for his distrust in the United States. He asks if Billie knew about Rayburn’s involvement, and when she says yes, he’s incredulous and asks how she could continue working for such a corrupt enterprise. The close friends trade jabs, with Stuart saying he can’t trust her anymore and Billie accusing him of always leaving.

When Eidra, the CIA station chief, gets wind of this, she also inserts herself and asks Stuart if he’s resigning. He’s not sure yet, but he tells her that he doesn’t know how he feels about working for these people and that he doesn’t “buy the story” anymore. Eidra counters with an argument that doesn’t exactly sell him on the morality aspect, saying that if he resigns it’ll be increasingly difficult to find another job and he’ll be trapped in debt. Stuart asks if she wants him to stay, and Eidra initially sidesteps the question. But he repeatedly asks her to say those words, and when she finally concedes, she jumps into his lap and kisses him.

With the submarine issues seemingly resolved, Kate’s focus returns to recommitting to her marriage. She asks Billie if there’s an extra seat back to Washington on Air Force 2, and when the room is cleared for her and Hal, she apologizes to him repeatedly. He takes her back, no questions asked, simply offering an “I’m still here. We’re still here.”

But things go belly up pretty quickly. Callum corners Kate in the hallway, not to talk about their personal relationship but to discuss a major professional development. The radiation levels in the ocean have dropped significantly, leading him to believe that the Russians have taken the submarine and Poseidon back. Kate immediately tells Hal, who tells the President, but his measured response tips her off. She asks him point-blank whether she and the President orchestrated an unauthorized extraction, citing her knowledge that Penn lied to Trowbridge about sending only a drone down to the submarine (in reality, the Americans sent down a submarine liner big enough to fit Poseidon).

All Hal says is, “You will tell no one,” before tipping off Penn with a “She knows.” As Kate and Todd watch from afar, Todd comments on his wife and her VP’s close relationship, which has troubled him all season. “Nothing to worry about, right?” he quips sarcastically. And while it’s not a torrid affair, the result could be much worse for Kate’s personal and professional life, and the world at large.