In season five, everyone is suspicious when resident tech nerd Roddy Ho has a glamorous new girlfriend. When a series of increasingly bizarre events occur across the city, it falls to the Slow Horses to work out how everything is connected. After all, Lamb knows that in the world of espionage, the London Rules — cover your back — always apply.

• Gary Oldman
• Jack Lowden
• Kristin Scott Thomas
• Hugo Weaving
• Saskia Reeves
• Christopher Chung
• Aimee-Ffion Edwards