The spying game

A glamorous but gritty drama of life inside the Special Intelligence Service, better known to you and me as the infamous MI5. The secret agent team, operating from The Grid in Thames House, London, have to deal with terrorist bomb threats, hostage takers, hackers and political corruption, as well as internal moles and inter-departmental rivalry. Its stories often have an eerie resonance with real life events.

The stakes are higher than ever for Adam, Harry and the team in season four as a series of terrorist attacks and political cover-ups threaten national security on an unprecedented scale.