Apple TV's Slow Horses has become one of the most acclaimed spy thrillers on television, boasting a stellar 98% Rotten Tomatoes score and a growing list of Emmy nominations. The show's sixth season just premiered, delivering the twists and turns fans have come to expect. With Season 7 already confirmed, the recent announcement of a Season 8 renewal seemed like a no-brainer. However, this long-term commitment brings with it a significant challenge that the creative team will need to navigate.
Faithful Adaptations So Far
Since its debut in 2022, Slow Horses has closely followed Mick Herron's bestselling Slough House novels. Each season has adapted one of the nine main books, starting with the first novel published in 2010. But Season 6 has shaken things up by combining two books—Joe Country and Slough House—into a single season. With Season 7 set to tackle the eighth book, Bad Actors, and Season 8 presumably aiming for Clown Town, the series is rapidly approaching the end of Herron's published material.
The Looming Question
Once Slow Horses exhausts the existing novels, what happens next? The show has already experienced a behind-the-scenes shift, with original showrunner Will Smith departing after Season 5. Gaby Chiappe took over for Season 6, and Ben Vanstone is slated to lead Season 7. This turnover adds uncertainty as the series nears the edge of its source material.
If the show continues beyond Herron's last book, it would need to forge an entirely original path. That's a daunting prospect, but not an impossible one. Other series have successfully expanded past their source material, like The Handmaid's Tale, The 100, and The Leftovers, each becoming unique entities by diverging from the original stories. The Slow Horses writing team is clearly talented, and they could likely craft compelling new adventures for Jackson Lamb (Gary Oldman) and River Cartwright (Jack Lowden) without a book to guide them.
Alternatively, the show could pause production and wait for Herron to publish another novel. That would break the annual release rhythm that has made Slow Horses a reliable favorite among streaming audiences. Or, the series could simply conclude with Season 8, wrapping up the story in a satisfying way that honors the books.
Fans will be watching closely to see which direction the show takes. Whether it embraces original storytelling or brings the saga to a close, one thing is certain: the end of Slow Horses will be a bittersweet moment for its devoted audience.
For now, Season 6 is streaming on Apple TV, with new episodes arriving every Wednesday. If you're looking for other shows that nail their endings, check out our list of Apple TV's best shows from premiere to finale. And if you're a fan of spy thrillers, you might also enjoy Dope Thief, another Apple TV+ gem.
