'Slow Horses' Season 5 premiere date: Showrunner Will Smith teases 'London Rules' and more (2025)

After another stellar six-episode installment filled with death, heartbreak, twists, humor, and addicting drama, Slow Horses Season 4 proved it’s still more than capable of playing this strange, strange game.

Season 4 of the beloved espionage thriller, based onMick Herron’s Slough House book series, followed misfit MI5 agents Jackson Lamb (Gary Oldman), River Cartwright (Jack Lowden), Louisa Guy (Rosalind Eleazar), Roddy Ho (Christopher Chung), Shirley Dander (Aimee-Ffion Edwards), Marcus Longridge (Kadiff Kirwan), Catherine Standish (Saskia Reeves), and new recruit J.K. Coe (Tom Brooke) as they raced to investigate a bombing and solve a mystery with Frank Harkness (Hugo Weaving) at the center.

Though the Slow Horses ultimately saved the day in the Season 4 finale, they lost several of their own in the process, and in the end, Frank used his failsafe get out of jail free card. With ongoing crises, unanswered questions, and more cases inevitably in need of cracking, Slow Horses has the storylines needed for another season. So is Slow Horses Season 5 coming to Apple TV+? We’ve got answers.

Curious if Slow Horses Season 5 is happening? When the Apple TV+ series returns with new episodes? And which Mick Herron novel will be adapted this time around? Decider spoke with Slow Horses showrunner Will Smith, who teased the future of his hit series and more.

Read on to learn everything we know aboutSlow HorsesSeason 5 on Apple TV+, including comments from the Emmy-winning showrunner himself.

Will There Be ASlow HorsesSeason 5 On Apple TV+?

Yes! Good news, Slough House stans. On January 2, 2024, just days after its third season concluded, Apple TV+ renewed Slow Horses for Season 5.

Slow HorsesSeason 5 Premiere Date: When DoesSlow HorsesReturn With New Episodes On Apple TV+?

When chatting with showrunner Will Smith about the Season 4 finale, he told Decider, “I honestly don’t know when [Season 5] will be out, but I can’t imagine that Apple would want to have it would be later than when [Season 4] went out.”

UPDATE 6/3/25: Apple TV+ announced that ghd highly anticipated fifth season of Slow Horses will premiere globally on Wednesday, September 24, 2025, with the first two episodes, followed by one episode weekly until October 22, 2025. Hooray!

How Many Episodes Are InSlow HorsesSeason 5?

LikeSlow Horsesseasons past, Season 5 will consist of six episodes. In keeping with tradition, the first two episodes ofSlow HorsesSeason 5 will premiere together on a Wednesday, and the series will follow a one-episode weekly release schedule until its finale.

Slow HorsesSeason 4 Ending Explained: What WillSlow HorsesSeason 5 Be About? Showrunner Will Smith Weighs In

If you’re looking fora detailed recap of theSlow HorsesSeason 4 finale, Decider’s Ending Explained article has you covered. As for major Season 5 storylines, however, Smith teased, “I can say that Roddy Ho comes to the fore. And part of what that involves is set up in Series 4. So there’s a little thing that happens in 4 that is connected to the main plot of Series 5. And so obviously with with Ho at the center it has a different feel to 4, which is a much more brutal and emotionally raw season. There’s still bad stuff happening, obviously. But you’ve got Ho. And more Coe. Coe starts to speak more, which is nice.”

In addition to Ho and Coe, Season 5 will also explore the aftermath of a major Slough House Season 4 death, particularly the effect it has on Shirley. “Marcus’ death will devastate Shirley, who never really opened up or got close to anyone in a way that we’ve seen before. She’s just going to be ripped apart from him,” Smith explained. We’ll also check in with other Slough House fixtures, watch River and David’s relationship continue to evolve, get a potential Frank Harkness return, and see how things work out at the Park for Claude and Diana.

Per Apple TV+, “In season five of Slow Horses, everyone is suspicious when resident tech nerd Roddy Ho has a glamorous new girlfriend, but when a series of increasingly bizarre events occur across the city, it falls to the Slow Horses to work out how everything is connected. After all, Lamb knows that in the world of espionage, the London Rules — cover your back — always apply.” As expected, Slow Horses Season 5 will be adapting another book in Mick Herron’s series, so let’s learn more. Shall we?

Which Mick Herron Book Does Slow Horses Season 5 Adapt?

Hooked on those teasers and want to know more? You can prep forSlow HorsesSeason 5 ahead of its release by reading Book 5 in Mick Herron’s series, titledLondon Rules,on which the new season will be based.

PerAmazon, theLondon Rulesplot summary is as follows:

At MI5 headquarters Regent’s Park, First Desk Claude Whelan is learning this the hard way. Tasked with protecting a beleaguered prime minister, he’s facing attack from all directions himself: from the showboating MP who orchestrated the Brexit vote and now has his sights set on Number 10; from the showboat’s wife, a tabloid columnist, who’s crucifying Whelan in print; from the PM’s favorite Muslim, who’s about to be elected mayor of the West Midlands, despite the dark secret he’s hiding; and especially from his own deputy, Lady Di Taverner, who’s alert for Claude’s every stumble. Meanwhile, the country’s being rocked by an apparently random string of terror attacks.

Over at Slough House, the MI5 satellite office for outcast and demoted spies, the agents are struggling with personal problems: repressed grief, various addictions, retail paralysis, and the nagging suspicion that their newest colleague is a psychopath. Plus someone is trying to kill Roddy Ho. But collectively, they’re about to rediscover their greatest strength- the ability to make a bad situation much, much worse.

Who’s Joining The Slow Horses Season 5 Cast?

In addition to returning fan favorite cast members, Slow Horses Season 5 will also welcome fresh faces like Nick Mohammed (Ted Lasso) and Hiba Bennani(Prime Target) to screen, per first-look images.

Will There Be ASlow Horses6?

Yes! Less than a week after its Season 4 finale, Apple TV+ renewed Slow Horses for Season 6. Per Deadline, “In Season 6, the spies head out on the run as Diana Taverner (Kristin Scott Thomas) embroils them all in a fatally high-stakes game of retaliation and revenge. The sixth season will be based on two of Mick Herron’s novels,Joe CountryandSlough House,which are the sixth and seventh in the book series.”

How Many Books Are in Mick Heron’s “Slough House” Series?

Heron has written standalone novels, short story collections, and several novellas throughout his career, but there are currently nine full novels in his “Slough House” series, listed in order of publication here:

• Book 1: Slow Horses (2010)
• Book 2: Dead Lions (2013)
• Book 3: Real Tigers (2016)
• Book 4: Spook Street (2017)
• Book 5: London Rules (2018)
• Book 6: Joe Country (2019)
• Book 7: Slough House (2021)
• Book 8: Bad Actors (2022)
• Book 9: Clown Town (2025)

With so much source material in the “Slough House” series, fans are likely wondering if the series will continue beyond Season 5. Though Apple TV+ has yet to officially renew the series for future seasons, Smith says he’d be open to making “really as many as Apple and Gary and the audience want.”

“My only kind of personal feeling on that is that I would always want the last season to be the best. I think every season has to be better. You know, I wouldn’t want the last season to be the last season because people felt that it was past its prime or peaked and now there was nothing more to do. You really want to sort of go out on top. And that’s the challenge — is not to repeat, and to feel it moving on, which the books do,” Smith continued. “…The characters, the ones who aren’t killed off, kind of wear the scars of what happened in the previous books and previous seasons. They’re building. They’re developing… So there’s always new things to be doing.”

The showrunner also told The Hollywood Reporter that “Mick has written a terrific book calledThe Secret Hours, which is a sort of sidebar book that fills in the backstory of Lamb, and he brings in all these other existing characters. It’s a wonderful book that I think there’s definitely an opportunity to do a shorter-run [series] or a film or something. I know Gary wants to keep going for as long as he’s asked. He loves playing the character.” So here’s hoping there’s much more Slough House in store for fans.

Stay tuned for more updates on Slow Horses Season 5 (and beyond). Until then, be sure to readDecider’s full interview with showrunner Will Smithand stream Slow Horses Season 4 on Apple TV+.