When does Slow Horses return?

Slough House is an administrative purgatory for MI5 service rejects who have bungled their job but have not been sacked. The series premiered on Apple TV+ on 1 April 2022. The second series, Dead Lions, premiered on 2 December 2022. In June 2022, the series was renewed for a third and fourth series. The fourth series will be based on the fifth book in the series, London Rules.
Slough House is an administrative purgatory for MI5 service rejects who have bungled their job but have not been sacked. They are expected to endure dull, paper-pushing tasks, along with occasional mental abuse from their miserable boss, Jackson Lamb. Yet they somehow get involved investigating schemes endangering Britain.