Slow Horses season 6: Release date speculation and latest news
What do we know so far about the hit spy drama's future?
*Warning: contains major spoilers for all six episodes of Slow Horses season 5*
An explosive finale has now brought the fifth season of Slow Horses to an end, wrapping up the adaptation of Mick Herron's London Rules.
The episode ended with plenty of story threads still left playing out, as Diana Taverner finally got what she had always wanted and River suggested he would be leaving Slough House for good.
Thankfully, fans of the books will know there is still plenty of material for the show to adapt in future seasons – in fact, just earlier this year a ninth novel in the series was released, and it doesn't seem like Herron will be slowing down on writing them any time soon.
But what do we know so far about the show's future, can we expect a sixth season to arrive on Apple TV and, if so, when will that be?
Read on for everything you need to know about Slow Horses season 6.
Will there be a Slow Horses season 6?
There will! In fact, season 6 was officially confirmed a long time ago, in October 2024, and a seventh season has also now been announced.
When the season 6 renewal was first confirmed, Jay Hunt, creative director for Apple TV+ in Europe, said in a statement: "Audiences around the world have fallen in love with the Slow Horses, and I’m delighted that Gary Oldman will be leading this star-studded cast on another acerbic and action-packed adventure."
One big change for this season will be the lack of involvement of Will Smith.
Smith, who acted as showrunner from the first season through to season 5, stepped down at the end of the most recent run.
He told Deadline earlier this year: "Series 5, it doesn’t end things by any means, but it concludes certain story arcs that started in season 1, so it felt like a good moment to hand over the show."
He explained his reasons for leaving the series, saying: "There’s two things. One, there’s the risk that you’ll start to run dry or repeat, which you have to watch. And so, it’s just getting ahead of that, and knowing when the right time is for you to give it over to somebody who can give it some new energy and freshness.
"And then it’s likely that the schedule of it just becomes something that can be slightly daunting after a while. It feels like I might not be giving you my best work if I continue at this pace…
"I do want to emphasise, it’s not in any way that I thought I’m now too good for Slow Horses. It’s much more that I want to keep being good enough for Slow Horses.
"And I would never want it to be like, 'Oh, that one wasn’t quite there.' It’s just that risk of just pushing it too far. And I just felt, I just want to go when I know I’m still delivering my very, very best for all the people that work on the show."
With Smith no longer involved, season 6 has been adapted by co-executive producer Gaby Chiappe. Meanwhile, the season has been directed by Adam Randall, having previously helmed season 4.
When will Slow Horses season 6 be released?
We don't yet know for certain when Slow Horses season 6 will be released, but we can make an educated guess based on the show's previous release pattern. The season has long since finished filming, so there shouldn't be any particular delay in it arriving.
While it has often dotted around the calendar, with seasons arriving in April, November and December in the past, for the past two runs it has seemingly become a more solid fixture in September.
We would therefore imagine that a September 2026 release date seems likely – although at this point, that does remain mere speculation.
We will keep this page updated as and when we get any more concrete details regarding season 6's release date.
What will Slow Horses season 6 be about?
The official synopsis for season 6 says it "sees the Slow Horses on the run as Diana Taverner embroils them all in a fatally high-stakes game of retaliation and revenge".
This certainly makes sense given where season 5 left off, with the show ending on the moment in which Taverner finally took her place as First Desk.
Roddy Ho star Christopher Chung told RadioTimes.com exclusively about how this would factor into season 6: "Going into the next season with Taverner in first desk, you've kind of got her in a position now where she's got everything that she's wanted, everything that she's plotted and schemed for.
"So it'll be interesting to see if absolute power corrupts. So I think that's a really good cliffhanger for the audience to see now that she's got her hands on the steering wheel where’s she gonna steer it?"
Beyond this, we know from the trailer that the season will see the return of Frank Harkness, and that it will see a file with the Slow Horses names in it being stolen, leading to the team being hunted.
Of course, we can also look to Mick Herron's novels for guidance – however, this time that may be more tricky than usual.
That's because, for the first time ever, the new season will adapt two of Herron's novels rather than one, suggesting the plots will be mashed up and changed more than ever in the adaptation process.
Still, the blurb for the first of the novels being adapted, Joe Country, says: "In Slough House, the backwater for failed spies, memories are stirring, all of them bad.
"Catherine Standish is buying booze again, Louisa Guy is raking over the ashes of lost love, and new recruit Lech Wicinski, whose sins make him outcast even among the slow horses, is determined to discover who destroyed his career, even if he tears his life apart in the process.
"With winter taking its grip Jackson Lamb would sooner be left brooding in peace, but even he can't ignore the dried blood on his carpets. So when the man responsible for killing a slow horse breaks cover at last, Lamb sends his crew out to even the score. This time, they're heading into joe country. And they're not all coming home."
Meanwhile, the blurb for the second novels being adapted, Slough House, says: "Slough House – the crumbling office building to which failed spies, the 'slow horses', are banished – has been wiped from secret service records. Reeling from recent losses in their ranks, the slow horses are worried they've been pushed further into the cold, and fatal accidents keep happening.
"With a new populist movement taking a grip on London's streets, the aftermath of a blunder by the Russian secret service that left a British citizen dead, and the old order ensuring that everything's for sale to the highest bidder, the world's an uncomfortable place for those deemed surplus to requirements.
"The wise move would be to find a safe place and wait for the troubles to pass. But the slow horses aren't famed for making wise decisions."
Who will star in Slow Horses season 6?
We already know that the majority of the central Slow Horses cast will be back, including Gary Oldman, Jack Lowden and Kirstin Scott Thomas.
In the trailer for season 6, which aired at the end of the season 5 finale, we also saw that Hugo Weaving is returning as Frank Harkness, while a number of new guest stars were revealed.
These appear to include Lenny Rush, who was previously seen filming for the season, as well as MyAnna Buring, Harry Lloyd, Kyle Soller and Lucian Msamati.
One star whose return is less certain is Rosalind Eleazar. Her character, Louisa Guy, left Slough House at the beginning of season 5, a move that departed from Mick Herron's novels. Whether she will come back in season 6 remains to be seen, and she was not present in any of the shots included in the trailer.
For now, here are all the stars we know will be in Slow Horses season 6, as they have been seen in the trailer:
- Gary Oldman as Jackson Lamb
- Jack Lowden as River Cartwright
- Kristin Scott Thomas as Diana Taverner
- Christopher Chung as Roddy Ho
- Saskia Reeves as Catherine Standish
- Aimee-Ffion Edwards as Shirley Dander
- Tom Brooke as JK Coe
- Ruth Bradley as Emma Flyte
- Hugo Weaving as Frank Harkness
- Naomi Wirthner as Molly Doran
- Lenny Rush as TBC
- MyAnna Buring as TBC
- Harry Lloyd as TBC
- Kyle Soller as TBC
- Lucian Msamati as TBC
Is there a trailer for Slow Horses season 6?
A trailer for Slow Horses season 6 played at the end of the season 5 finale, but as has been the case with previous seasons, it hasn't yet been made available online.
It seems we will have to wait until nearer the time for a trailer to be released online, but for now you can rewatch the season 5 trailer right here.
Slow Horses seasons 1-5 are available to watch now – sign up to Apple TV here.
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Authors
James Hibbs is a Drama Writer for Radio Times, covering programmes across both streaming platforms and linear channels. He previously worked in PR, first for a B2B agency and subsequently for international TV production company Fremantle. He possesses a BA in English and Theatre Studies and an NCTJ Level 5 Diploma in Journalism.
