Slow Horses Season 6 features Sid Baker's return and new assassins

The sixth season of the Apple TV+ spy thriller ‘Slow Horses’ has introduced major plot developments and character returns. In the second episode, titled ‘Daddy Issues’, the series features the unexpected return of Sidonie ‘Sid’ Baker, played by Olivia Cooke, who was previously presumed dead after being shot in the first season.

The narrative follows a series of targeted killings involving former Slough House agents, including Struan Loy, Kay White, and Moira Tregorian. These deaths, orchestrated by assassins Jim and Jane, are staged to appear as accidents. Simultaneously, the plot involves a stolen MI5 file and the involvement of Frank Harkness, which heightens the security crisis for Jackson Lamb and his team.

Production details reveal that director Adam Randall has taken an expanded role this season as an executive producer and writer, focusing on the character-driven nature of the series. The third episode, ‘Resurrection’, is scheduled for release on September 30, 2026.