Apple TV has released the official trailer for Slow Horses Season 6, and there is a very familiar face waiting at the end of it. Gary Oldman returns as Jackson Lamb when the Emmy and BAFTA-winning spy drama premieres on Wednesday, 16 September 2026, with Olivia Cooke unexpectedly returning as Sid Baker four years after her last appearance.
When Is Slow Horses Season 6 Released?
Slow Horses Season 6 premieres globally on Apple TV on Wednesday, 16 September 2026. The new season once again consists of six episodes, but there will be no full-season binge. Apple has confirmed that one episode will arrive each Wednesday, taking the story through to the finale on 21 October.
Slow Horses Season 6 Full Release Schedule
There are six episodes in Slow Horses Season 6. The complete release schedule is:
Wednesday, 16 September – Episode 1
Wednesday, 23 September – Episode 2
Wednesday, 30 September – Episode 3
Wednesday, 7 October – Episode 4
Wednesday, 14 October – Episode 5
Wednesday, 21 October – Episode 6, Finale.
What Is Slow Horses Season 6 About?
Things are not looking particularly good for the residents of Slough House this time around. Apple says the new season sees the Slow Horses forced on the run after Diana Taverner pulls them into a deadly game of retaliation and revenge. The trailer shows Lamb becoming increasingly concerned as people connected to Slough House start turning up dead, prompting him to gather the team together and order them to disappear off the grid. Naturally, his instruction to stay away from their phones does not go entirely to plan.
Season 6 adapts Joe Country and Slough House, the sixth and seventh novels in Mick Herron’s book series.
Is Sid Baker Alive in Slow Horses?
Well, apparently so. The biggest surprise in the trailer comes right at the end when River Cartwright finds Olivia Cooke’s Sid Baker waiting for him at the top of a staircase. Sid was shot during the first season and subsequently believed to have died, although the disappearance of her MI5 records had already left the door open for her survival. Cooke has not appeared in the series since Season 1, making her return one of the biggest unanswered storylines Slow Horses has finally decided to revisit. Apple has now officially confirmed that she will reprise the role in Season 6.
Who Is in the Slow Horses Season 6 Cast?
Gary Oldman is back as Jackson Lamb, with Jack Lowden returning as River Cartwright and Kristin Scott Thomas as Diana Taverner.
Saskia Reeves, Christopher Chung, Aimee-Ffion Edwards, Rosalind Eleazar, Joanna Scanlan, Samuel West, Ruth Bradley, Tom Brooke, Jonathan Pryce and Hugo Weaving also return. Lenny Rush joins the cast for the new season, with Olivia Cooke reprising her role as Sidonie “Sid” Baker.
Is There a Slow Horses Season 6 Trailer?
Yes. Apple TV released the official trailer on 18 August, giving us our best look yet at the trouble heading towards Slough House. There are explosions, shootouts, plenty of Jackson Lamb insults and a team seemingly being hunted one by one, before the trailer saves its biggest reveal for the final seconds with Sid’s return.
Have a look at the trailer below.
For CultureCues, Slow Horses remains one of our favourite shows on Apple TV, and this trailer has made the September wait even harder. Gary Oldman as Jackson Lamb is always reason enough to watch, but bringing Olivia Cooke back as Sid after all this time is such a brilliant surprise. We have been wondering whether she was really dead since Season 1, and seeing River come face-to-face with her again immediately gives us another mystery we need answers to. Six weeks of waiting between episodes is going to test our patience, but we will absolutely be there every Wednesday… Slough House, here we come.
Slow Horses Season 6 premieres on Apple TV on Wednesday, 16 September 2026, with new episodes released weekly through to the finale on 21 October. The first five seasons are available to stream now.
Nikki Murray is a UK-based writer, screenwriter and founder & editor of CultureCues, covering film, television, music and pop culture. Her work focuses on storytelling and the moments shaping modern entertainment.