At long last, welcome back to Slough House.
With the arrival of the sixth season of Slow Horses, Apple TV returns the viewer to the dysfunctional team of British intelligence agents of Slough House, a dumping ground for MI5 undesirables. Led by the irritable Jackson Lamb (Gary Oldman), this team of spies are filled with those who have marred their careers and have nowhere else to go.
Yet, every broken piece has its place and the misfits of Slough House continue to fight the good fight, even as they fight for redemption. To them, Slough House is essentially a safe space for them to prove their worth by showing that they’re more than their greatest mistakes. In essence, it becomes a home for broken souls.
And, in Season Six, Slow Horses strips all that away.
With the return of Horses, the team from Slough House finds themselves slowly being erased. Former members are dying mysteriously and MI5 seems to have disavowed their team. This adds a darker element to the series, forcing the team out of their home base and setting them on the run. It’s a fun change to the shows format that heightens the tension and pushes the team out of their comfort zones. As always though, it’s not merely the procedural element that makes these Horses run so well.
It’s Oldman.
Don’t get me wrong. The series has incredible supporting performers. Jack Lowden’s River continues to be the series’ eyes and broken heart while the rest of the team battle their own demons. And, of course, the elevation of Kristin Scott Thomas to the head of MI5 gives her much more power within the organization (and, by extension, makes her character more central).
However, its Oldman that continues to be the glue that holds Horses together. Returning as the grizzled veteran, Jackson Lamb, the actor never ceases to pop onscreen. As Lamb, Oldman’s presence grounds the series, balancing the gravitas with a sense of humour. His laissez-faire attitude is peppered with an adorable grumpiness that makes him endearing, even when the world is falling apart. (Just watch the way that he handles Slough House’s pay stoppage in the premiere. You’ll realize how much you missed him.)
Of course, much has been made about the return of Olivia Cooke in the role of Sid. In a lot of ways, it’s almost odd how celebrated Cooke’s return has become. Although her character remains beloved by fans, her time in the series until now only amounted to a mere three episodes in the first season. Even so, her star has only continued to rise outside of Horses and her return as Sid is more than welcome to the series. Her’s is a return mired in hope as the Cooke emerges from the shadows to disturb the lives of River and the team.
But, to be fair, River’s life is already in deep distress upon her arrival.
After the passing of his grandfather, Lowden’s River is buried under the weight of his own grief. Despite the warnings of his friends and co-workers, he returns to work in the hope of distracting himself from his own inner turmoil. And this theme of grief pervades the series as the team struggles to deal with the loss of (several) members of their team. Some handle their hurt by neglecting their feelings. Others seem to dance with their personal demons. (Without saying too much, Saskia is clearly one of the latter.)
As such, there’s definitely a bit of a darker edge to the new season. While the previous series’ tone never shied away from heavier themes, this year Horses seems to up the stakes for its characters. By moving them out of Slough House, the team genuinely find themselves without their home, creating greater instability amongst them.
And that’s what makes it great television.
The premiere of Slow Horses is available on Apple TV on Wednesday, September 16th, 2026, with new episodes premiering weekly afterwards.
