Slow Horses is a British spy thriller television series based on the Slough House novels by Mick Herron. It follows an MI5 unit where disgraced or failed agents are consigned. The series premiered on Apple TV+ on 1 April 2022 to highly positive reviews. The first four series have been based on novels Slow Horses, Dead Lions, Real Tigers, and Spook Street respectively. The fifth and sixth series is slated to premiere on 24 September 2025. In July 2025, the series was renewed for a seventh series which is to be based on Bad Actors.
Slough House is an administrative purgatory for MI5 service rejects who have bungled their job but have not been sacked. Those consigned there are known as "slow horses" - a pun on "Slough House" They are expected to endure dull, paper-pushing tasks, along with occasional mental abuse from their miserable boss, Jackson Lamb.