Slow Horses season seven adds Varada Sethu and Tuppence Middleton

Slow Horses has added five actors to its seventh season. Varada Sethu, Tuppence Middleton, Ethan Moorhouse, Merab Ninidze and Joshua McGuire join the Apple TV spy drama, with the casting announced on October 19, 2026. Their character details have not been disclosed.

James Callis will also return as Claude Whelan alongside Gary Oldman’s Jackson Lamb. The six-episode season adapts Bad Actors, the eighth novel in Mick Herron’s Slough House series. Its central investigation sends Lamb and his team searching for a mole within the British government before the infiltrator can bring down the state.

The series follows intelligence officers whose mistakes have landed them at Slough House, an unglamorous MI5 posting overseen by the abrasive Lamb. For season seven, Ben Vanstone handles the television adaptation and serves as an executive producer, with Robert McKillop directing. See-Saw Films produces the series for Apple TV.

This is a casting update, not a new renewal announcement: Apple ordered season seven in July 2025. A premiere date has not yet been announced.