Apple TV's 'Slow Horses' Season 6 Trailer Reveals Major Character Returns

Apple TV has established itself as a notable player in the streaming landscape, particularly in the spy thriller genre, with its acclaimed series 'Slow Horses.' This show, featuring Gary Oldman and Jack Lowden, follows the misfit agents of MI5 and their often chaotic missions. As anticipation builds for the upcoming Season 6, the newly released trailer not only teases the plot but also reveals the return of three significant characters that fans have been eager to see again.

The trailer opens by introducing a central mystery: former Slough House employees are being targeted and eliminated. This premise sets the stage for a thrilling season filled with suspense and intrigue. Among the returning characters is Louisa Guy, portrayed by Rosalind Eleazar, who left the series in the previous season but is drawn back into the spy world.

Perhaps the most notable return is that of Sidonie "Sid" Baker, played by Olivia Cooke. Last seen in Season 1, Sid's return is expected to have major implications for River Cartwright, as unresolved guilt from their past interactions looms over him. Fans familiar with Mick Herron's source material will recognize the significance of her character's reappearance, especially given her previous role as a spy assigned to monitor River.

Additionally, the trailer hints at the return of Hugo Weaving's Frank Harkness, the central antagonist from Season 4. Although his role in the upcoming season appears to be brief, his character is likely to serve as a significant foil to River, complicating the narrative as the plot unfolds.

'Slow Horses' is set to premiere its first episode of Season 6 on September 16, 2026, with new episodes released weekly until October 21, 2026. As the series continues to explore the complexities of espionage and personal relationships, fans can expect a captivating blend of drama and suspense in the new season.