If you’re a sucker for a tense political thriller, you’ve likely already seen trailers for The Diplomat. The Netflix original series, which premiered in April 2023, has finally released its third season, to a variety of stunned reactions. For those that don’t know, the show centers on Kate Wyler, an American diplomat hired to mitigate a complex geopolitical conflict in the United Kingdom. Over the course of the first two seasons, she manages to uncover a massive web of political conspiracies, all while fighting for her life and playing the bizarre and gritty game of politics. The third season of The Diplomat is the most action-packed entrant into the series thus far, offering plenty of shocking reveals, calculated alliances and instances of political violence.

Whether you’re too locked in to the world of real-life political affairs to keep up, or just struggling to parse through some of the twists and turns of the show, be sure to read ahead. We’ll outline the plot, characters, and conclusion of The Diplomat, and look ahead at what season four might offer us. Needless to say, there will be full spoilers for the series ahead, so be sure to proceed with caution if you’re not fully caught up. With no further preamble, let’s dive right in, and unpack the chaos of The Diplomat season three.

How did season two of ‘The Diplomat’ end?

For those that may not remember, season two of The Diplomat concluded on an intense cliffhanger. Having discovered that Vice President Grace Penn was directly involved in a series of firebombing attacks on England, Kate and her husband Hal frantically attempt to warn their peers about Penn’s treason. Penn’s plot was carried out in order to maintain control over an important nuclear facility and submarine docking port in Scotland, which was in danger of being shut down by a democratic referendum. As part of a mad dash to oust Penn, Hal gets on a video call with the president directly, and tells him everything. Unfortunately, this plan backfires tremendously, as the shock of this news immediately triggers the president to have a heart attack, killing him instantly.

In the final moments of the season, Penn is informed by her secret service detail that she has been promoted to the role of POTUS, giving her even more power and influence than ever before. Kate and Hal look on in horror, as they realize that they’re effectively the last line of defense to prevent Penn from carrying out any number of terroristic assaults on democracy foreign and domestic.

Does Kate become Vice President?

With President Rayburn dead and buried, Penn begins choosing new members for her cabinet. Having risen through the ranks in previous years, Kate expects to be on the shortlist for a VP pick, and even considers a future presidential run. Instead, Penn chooses Hal as her Vice President, which causes Kate to lash out in frustration. Hal has effectively been a lame duck since The Diplomat‘s first season, after previous controversies ended his political career.

Instead of sitting back and allowing Kate’s career to blossom, however, he used her rising star power to bring himself back into the limelight, effectively catapulting himself into the West Wing. At first, it looks like Kate will have to accept the symbolic and empty position of Second Lady, though she and Hal agree to undergo a “secret divorce” so that she can maintain her position as special ambassador to the UK.

With Hal in the White House and Kate overseas, the couple wind up holding a significant amount of political power. This becomes especially apparent when a Russian submarine is downed in the East Atlantic, dropping a powerful nuclear doomsday weapon just off the coast of England. Since Prime Minister Trowbridge has limited foreign policy knowledge, Hal and Kate are able to work together to advise him with a direct line to the President.

Unfortunately, it soon becomes clear that the United States military was responsible for downing the Russian sub in foreign waters, which could spark a massive war if discovered. Kate advises Trowbridge to bury the sub so no foreign power can take possession of the nuke, only to learn that Penn and Hal have already arranged to pick it up and bring it to the United States.

What happens at the end of season three of ‘The Diplomat’?

Penn and Trowbridge hold a series of joint press conferences to mitigate the fallout of the nuclear scandal and eschew any culpability in the attack. Kate advises them both to pin the entire situation on the now deceased President Rayburn, in order to sidestep any responsibility. Several Russian nationals were killed during the attack, making it an act of war if publicly discovered. Penn dismisses Kate’s idea, though Trowbridge ultimately breaks his silence and publicly blames Rayburn, claiming the attack was one of his final orders before his passing.

Just when it looks like Kate finally has a leg up on her peers, she learns that Trowbridge is taking secret meetings with Chinese operatives, signaling that he may be planning to recover the sub with the help of the Chinese government. This would only serve to escalate tensions, and potentially spark a world war. Before Trowbridge can even attempt to retrieve the sub, however, Kate pieces together that Hal and Penn have already done it. Thanks to a hot tip from a British special forces operative, Kate learns that radiation levels around the sub have dropped by over 60 percent in the days following a reconnaissance mission from Penn’s officials.

As season three of The Diplomat comes to a close, the British think the Russians have the bomb, the Russians think the British have the bomb and the United States President is an unabashed war criminal with the most powerful weapon ever developed at her disposal. Meanwhile, the Chinese government is involved as part of a secret undercurrent of espionage, meaning international tensions have never been higher.

When does season four of ‘The Diplomat’ come out?

In season four of The Diplomat, Kate will likely be tasked with single-handedly mending international relations to prevent a third world war. If she fails this mission, the show could conclude with an apocalyptic armed conflict the likes of which have never been seen. For now, we’ll just have to wait and see how it all shakes out.

Luckily, Netflix has been pretty quick on the draw with the release of new seasons for this show. Unlike some modern series, which take multiple years in between installments, The Diplomat has rapidly cranked out releases each year. Netflix hasn’t provided an exact release date for the next batch of episodes just yet, though it seems likely that we’ll see Kate and company return in fall 2026.

During a recent discussion with Netflix’s Tudum, creator and executive producer Debora Cahn gushed about the future of the series, stating “I’m so excited about season four. 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.’” She continued to discuss her high-stakes writing ideas, warning that fans, “Should be worried. There’s plenty to worry about. It can be pretty chilling when you see who takes power and get the sense that they may be horrifically misusing it.”

Frequently Asked Questions

Who plays Callum in The Diplomat?

The character of Callum Ellis appears in the third season of The Diplomat. He serves as a mysterious operative for the British special forces, as well as a potential love interest for Kate. The character is brought to life by Irish actor Aidan Turner, who has previously appeared in the Hobbit film trilogy as Kíli, the dwarf.

Where is The Diplomat filmed?

The Diplomat is primarily filmed on location in London, England. Most of the backdrops and historical sites used in the series are genuine, and not brought to life via soundstage or green screen. Though much of the show takes place right in the heart of London, the production has also moved all across the English countryside, capturing sequences in Greenwich, Hertfordshire, Westminster and beyond, per Tudum.