When a defecting KGB officer reveals the existence of a devastating Soviet plot, codenamed Operation Glass, the charismatic but paranoid head of MI5, known simply as Daddy (Cox), assembles a secret committee to investigate.
Maybe they're the best, maybe they're just the ones he trusts. They are Bobby Waterhouse (Ritter), the louche and ambitious head of counter-espionage; Sarah Montag (Hamilton), his dry-witted and fiercely clever deputy; her husband Alan (Aris), the ‘nosey-parker’, their cheerful and guileless expert in bugging and interception; Jim Fenchurch (Dooley), a stoic and sceptical Special Branch detective; Wendy Straw (Pirrie), the naïve and impressionable secretary. The final operative is Joe Lambe (Hughes), the troubled but genius interrogator, able to read every tic and turn of human nature, but hiding dark secrets of his own. (http://www.bbc.co.uk/mediacentre/latestnews/2013/the-game-casting-announcement.html)