Slow Horses Season 6 arrives on Apple TV on September 16, 2026, bringing back Gary Oldman as Jackson Lamb, Jack Lowden as River Cartwright, and the troubled intelligence team at Slough House. The six-episode season adapts Mick Herron’s novels Joe Country and Slough House and puts the Slow Horses on the run after Diana Taverner becomes involved in a dangerous campaign of retaliation and revenge.
For viewers searching for release details, cast information, story setup, episode schedule, and where to watch, the new season now has a confirmed launch date and weekly rollout. The official trailer has also revealed several familiar faces returning.
Slow Horses Season 6 release date and schedule
Slow Horses Season 6 premieres Wednesday, September 16, 2026, exclusively on Apple TV. It contains six episodes, with a new episode arriving each Wednesday through October 21.
| Episode | Release date | Title |
|---|---|---|
| 1 | September 16, 2026 | Circle of Life |
| 2 | September 23, 2026 | Daddy Issues |
| 3 | September 30, 2026 | Resurrection |
| 4 | October 7, 2026 | Lost & Found |
| 5 | October 14, 2026 | Sayonara |
| 6 | October 21, 2026 | Judgement Day |
Apple TV confirms the six-episode format and October 21 finale. The episode titles and dates are also listed by TheTVDB.
What is the story about?
Slow Horses Season 6 has a deliberately brief official premise: the Slow Horses are on the run, while Diana Taverner draws them into a high-stakes situation driven by retaliation and revenge.
The season adapts Joe Country and Slough House, the sixth and seventh books in Herron’s Slough House series. That is a notable change from earlier seasons, which generally focused on one novel.
The trailer adds more clues. Anonymous assassins hunt members of the team, bringing former Slow Horse Louisa Guy back into the action. Another major development is the return of Sidonie “Sid” Baker, played by Olivia Cooke.
Sid’s comeback is particularly significant for long-time viewers. Her apparent death in the first season left one of the show’s biggest unresolved questions. The Slow Horses Season 6 trailer confirms Cooke’s return, although the circumstances surrounding Sid remain part of the mystery.
Slow Horses Season 6 cast and returning characters
Gary Oldman returns as Jackson Lamb, the foul-mouthed but highly capable head of Slough House. Jack Lowden is back as River Cartwright, while Kristin Scott Thomas reprises Diana Taverner.
The returning ensemble also includes Saskia Reeves as Catherine Standish, Christopher Chung as Roddy Ho, Aimee-Ffion Edwards as Shirley Dander, Rosalind Eleazar as Louisa Guy, Joanna Scanlan, Samuel West, Ruth Bradley, Tom Brooke, Jonathan Pryce, and Hugo Weaving.
Olivia Cooke returns as Sidonie “Sid” Baker, while Lenny Rush joins the cast as a new addition. The ensemble remains central because its tension comes from clashing personalities as much as espionage.
Lamb’s abrasive leadership, River’s determination, Taverner’s political instincts, and the team’s unreliable reputation create conflict before the central threat fully emerges.
Why this season could feel different
The decision to adapt two novels gives the sixth season a broader source foundation than previous installments. Joe Country and Slough House come later in Herron’s sequence, so readers may recognize underlying story elements, while television viewers can follow the plot without reading the books.
There is also a change behind the camera. Gaby Chiappe serves as co-executive producer and adapted the season for television, while Adam Randall returns to direct. The series is produced for Apple TV by See-Saw Films.
Sid’s return is the clearest link to the show’s past, while the larger story appears focused on consequences. The Slough House agents have spent years surviving missions that powerful people would rather forget. Season six puts that history under direct pressure.
💡 Pro Tip
If you are planning a full-series rewatch, watch the first five seasons before the new episodes. Pay particular attention to Sid’s season-one storyline and the changing relationship between River, Lamb, and Taverner. Those threads make the sixth-season setup easier to follow without spoilers.
Where to watch Slow Horses Season 6
Slow Horses Season 6 will stream on Apple TV from September 16, 2026. Apple’s official listing confirms that the service carries the series, while the first five seasons are already available there.
The show is rated TV-MA in the United States and 15 in the UK according to Apple’s regional listings. Details can vary by country.
For someone new to the series, starting with the sixth season is not ideal. The show has continuing characters and serialized relationships, and later events build on earlier decisions. Watching the first five seasons gives the new story much more context.
What fans should expect
The strongest reason to watch is the combination of espionage and character-driven tension. Slow Horses does not rely only on spy gadgets or action scenes. Its appeal comes from flawed intelligence officers making difficult decisions while senior figures manipulate events.
Season 6 appears to push that formula into a more dangerous direction. The team is being hunted, Taverner is caught in a retaliatory conflict, and familiar characters are returning as their pasts become relevant.
For existing viewers, the Sid storyline is likely to be a major draw. Newer audiences will get more from the season after watching the earlier episodes.
📌 Key Takeaway
Slow Horses Season 6 premieres September 16, 2026, with six weekly episodes ending October 21. Gary Oldman, Jack Lowden, Kristin Scott Thomas, and the core ensemble return, while Olivia Cooke’s Sid Baker makes a major comeback. The season adapts Joe Country and Slough House and centers on the team being hunted amid Taverner’s dangerous game of retaliation and revenge.
Frequently Asked Questions
When does Slow Horses Season 6 come out?
The sixth season premieres September 16, 2026, on Apple TV. Six episodes will release weekly on Wednesdays, with the final episode scheduled for October 21. It is a weekly release rather than a full-season drop.
How many episodes are in Season 6?
There are six episodes. Apple TV confirmed the format, with the first arriving September 16 and subsequent episodes appearing each Wednesday through October 21.
Is Olivia Cooke returning as Sid Baker?
Yes. Olivia Cooke reprises Sidonie “Sid” Baker. Sid was apparently killed during the first season, making her return one of the most significant developments in the new trailer. The season will explore the circumstances behind her reappearance.
Which books does Season 6 adapt?
The season adapts Joe Country and Slough House, the sixth and seventh novels in Mick Herron’s Slough House series. The television story therefore draws from two books rather than one.
Where can I watch the new season?
The new episodes will stream on Apple TV. The service also carries the earlier seasons, allowing viewers to catch up before the sixth-season premiere.
The countdown is now clear: the first episode arrives September 16, followed by five more Wednesdays and a finale on October 21. With Jackson Lamb back at Slough House, Sid returning, and the team facing a threat that puts them on the run, the new season has several established story threads to bring together.
