Ahead of its season 6 release in September 2026, Apple TV renewed Slow Horses for an eighth season. The renewal made the British spy thriller series the longest-running show on the streamer, and fans seemed pretty happy. Why wouldn’t they be? While other great shows are getting canceled or wrapping up their stories, Slow Horses just keeps on running, and there doesn’t seem to be an end in sight.
Yet season 8 could inspire some big behind-the-scenes decisions for those shepherding the TV version of Mick Herron’s bestselling book series onto the small screen, as it will adapt the events of his most recent Slough House entry, Clown Town. After season 8, the Apple TV series could be up to date with Herron’s beloved tales of hapless espionage, which may mean some changes ahead.
Slow Horses typically releases a season every year, so season 8 could realistically arrive in 2028. Herron isn’t done writing Slough House books, but if he doesn’t release another one (or even two) in good time before then, the series will be faced with a few choices: keep going with the writing team’s own ideas à la Game of Thrones, consult with Herron about any firm or detailed ideas he has for future instalments, delay work on further seasons and wait for the author to create more books, or put an end to the show.
Herron has churned out nine Slough House novels and five novellas since 2010, so we can’t imagine Slow Horses fans will be left dealing with a Winds of Winter-esque situation here, but a lack of source material is already something that the creators of the series have had to consider.
