If you’re already dying to meet the unlucky River, the annoying Roddy, the depressive Catherine, and the repulsive Jackson Lamb again, we have good news: the official trailer for season 5 of Slow Horses has arrived.
The espionage series, based on Mick Herron’s series of novels, is one of the most exciting productions on Apple TV+. The British show provides a real feast for spy fans, quite different from the bombastic adventures of James Bond or Ethan Hunt.
Apple’s series combines engaging puzzles with black humour and charismatic characters. The leader is the misanthropic, slobby, ruthless and incredibly effective Lamb, played by the incomparable Gary Oldman.
Here’s all you need to know about the fifth instalment of Slow Horses.
When will Slow Horses season 5 be released?
The fifth instalment of the espionage series will debut on Apple TV+ on Wednesday, 24 September 2025. The season consists of six epispdes that will premiere on the service weekly.
An Apple TV+ monthly subscription costs $12.99 per month in the US and £9.99 per month in the UK.
Apple TV+
What will the plot of Slow Horses season 5 be?
Spoilers for season 4 below.
The show’s new season will be based on the fifth book by Mick Herron, London Rules.
The official synopsis for season 5 reads:
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.
In the novel, a series of assassinations are yet again taking place in London. Claude Whelan, the First Desk, along with his deputy and rival, Diana Taverner, are trying to bring the situation under control… but it’s proving extremely difficult.
The Slough House team gets into trouble as usual. River and the other agents have to face not only their work but also personal problems and traumas.
Apple TV+
In the new instalment, River will likely struggle with remorse over placing his dementia-suffering grandfather in a nursing home. Another issue that is likely to haunt him is the truth about his parents. Perhaps in the fifth season, we will finally meet River’s mother, who hasn’t kept in touch with her son and her father for years.
The ending of season 4 suggested that River might form a certain bond with Jackson Lamb. However, given the attitude of the head of Slough House, this may be a false hope. Instead, the real support for River may be Louisa, with whom he began to befriend at the beginning of season 4.
Remorse will probably also haunt Shirley – the drug-addicted agent will have to deal with her grief over Marcus’ death.
We could also learn more about the new member of Slough House – the silent and extremely disturbing JK, who showed his very dark side in the season 4 finale. We hope that the show’s creators will give us more scenes with this mysterious character.
Is there a trailer for Slow Horses season 5?
Yes! Here’s the official trailer for the fifth season:
You can also watch a short teaser, which was unveiled after the final episode of season 4.
Who are the cast and crew of Slow Horses season 5?
In the fifth season of the espionage series, we will see the return of most of the characters:
- Gary Oldman – Jackson Lamb
- Jack Lowden – River Cartwright
- Saskia Reeves – Catherine Standish
- Rosalind Eleazar – Louisa Guy
- Aimée-Ffion Edwards – Shirley Dander
- Christopher Chung – Roddy Ho
- Tom Brooke – JK Coe, the new member of the Slough House
- Ruth Bradley – Emma Flyte, the new Head of the Dogs
- James Callis – Claude Whelan, the new First Desk
- Kristin Scott Thomas – Diana Taverner, Director-General of MI5
- Jonathan Pryce – David Cartwright, River’s grandpa
Nick Mohammed, known from portraying Nathan Shelley in Ted Lasso, will guest-star in season 5.
Sadly, in season 5, we won’t see Kadiff Kirwan as Marcus Longridge – the gambling-addicted agent met a tragic end in the season 4 finale.
Apple TV+
It is unclear whether we will see Joanna Scanlan as Moira Tregorian in the new episodes – in the season 4 finale, the clerk cemented her return to The Park.
Whether Hugo Weaving will return to the series as Frank Harkness also remains a mystery. The later fate of this ex-spy and paid assassin hasn’t been fully explained. In season 4, he was arrested by MI5, but he was certain of his release. As writer Will Smith teases, Harkness reappears in the books, so there’s a chance for his comeback in the Apple TV+ series.
Will there be season 6 of Slow Horses?
Yes! Apple has already ordered the sixth instalment of the show. The following season will be based on Herron’s sixth novel from the Slough House series, Joe Country.
