Slow Horses season 6 is officially coming to Apple TV on September 16, 2026, with a new trailer teasing a deadly threat against Slough House. Jackson Lamb and his team are being hunted, forcing them into hiding. Olivia Cooke also makes a surprise return as Sid Baker.
The six-episode season runs weekly through October. Keep going to catch the trailer’s biggest moments, returning faces, and key release details.
What Does the Slow Horses Season 6 Trailer Reveal?
The Slow Horses season 6 trailer reveals that current and former Slough House agents are being targeted, forcing Jackson Lamb and his team to go underground. The footage builds around the mystery of who is killing the Slow Horses before ending with its biggest surprise, Olivia Cooke‘s return as Sid Baker.
What Happens in the Slow Horses Season 6 Trailer?
Image © 2026 Apple TV
The trailer opens with Jackson Lamb (Gary Oldman) confronting Diana Taverner (Kristin Scott Thomas) and asking, “Do you know anything about why my Slow Horses keep turning up dead?” Catherine Standish (Saskia Reeves) warns that anyone who has ever worked at Slough House is being targeted, leading Lamb to declare, “It’s a bloodbath.“
Lamb sends the surviving agents to a safe house and orders them to disappear, telling them, “Stay dark, yeah? No phones.” Louisa Guy (Rosalind Eleazar) and other former Slough House figures are pulled back into danger as the team tries to protect those being targeted.
The action intensifies in the second half with explosions, shootouts, fights, and high-stakes pursuits. Frank Harkness (Hugo Weaving) also makes an appearance, while those behind the attacks remain a mystery. The official logline describes the conflict as a “fatally high-stakes game of retaliation and revenge.“
- Main Threat: Current and former Slough House agents are being hunted.
- Safe House: Lamb orders the team to go underground and stay off their phones.
- Louisa Guy: The former Slough House agent is pulled back into the danger.
- Frank Harkness: River’s father appears during the action-heavy trailer.
- Big Mystery: The trailer does not reveal who is killing the Slow Horses or why.
Who Returns in the Slow Horses Season 6 Trailer?
Image © 2026 Apple TV
The trailer’s biggest reveal comes when River Cartwright (Jack Lowden) sees Sid Baker (Olivia Cooke) alive. After Lamb jokes, “We’ve all faked our own death at one time or another,” Sid appears and simply says, “Hello, River.“
Several familiar faces also return as Slough House searches for former agents who could be in danger. Frank Harkness and Louisa Guy appear again, while Moira Tregorian (Joanna Scanlan) is also glimpsed. Struan Loy (Paul Higgins) appears briefly, although his return has not been formally confirmed.
- Sid Baker: Olivia Cooke returns for the first time since Season 1.
- Frank Harkness: Hugo Weaving appears again as River’s father.
- Louisa Guy: Rosalind Eleazar is shown returning amid the Slough House crisis.
- Moira Tregorian: Joanna Scanlan is among the familiar faces shown in the trailer.
- Struan Loy: Paul Higgins appears to be glimpsed, but his return remains unconfirmed.
When Does Slow Horses Season 6 Premiere on Apple TV?
Image © 2026 Apple TV
Slow Horses season 6 premieres globally on Apple TV on Wednesday, September 16, 2026, bringing Jackson Lamb and the Slough House team back less than a year after Season 5. The six-episode season will roll out weekly, with the finale arriving on October 21.
This time, the series takes on two Mick Herron novels, Joe Country and Slough House, the sixth and seventh books in the series. The combined adaptation sets the stage for the deadly hunt teased in the trailer and Sid Baker’s long-awaited return.
- Premiere Date: September 16, 2026.
- Episode Count: Six episodes.
- Release Schedule: Episodes arrive weekly.
- Finale Date: October 21, 2026.
- Where to Watch: Slow Horses Season 6 streams on Apple TV.
Final Thoughts
Slow Horses Season 6 brings the Slough House drama back, with a cast facing another dangerous threat. The sixth series is adapted from two books, Joe Country and Slough House, while Diana Taverner’s role as First Desk adds another layer to the story.
Sid Baker finally returns, bringing an old mystery back to life. For more posts from the world of Slow Horses, keep following the latest Season 6 updates.
FAQs
Yes, Slow Horses Season 7 has already been confirmed by Apple TV.
Yes, Jack Lowden returns as River Cartwright in Slow Horses Season 6.
Yes, Rosalind Eleazar returns as Louisa Guy and appears in the Slow Horses Season 6 trailer.
Slow Horses Season 6 has six episodes, released weekly from September 16 through October 21, 2026.
Slow Horses is primarily filmed in London, England, where the Apple TV spy series is set.