Deception is at the heart of what it means to be a spy – what kind of person becomes a spy, and what qualities do the very best possess?For some of the most notorious spies in British history in both fact and fiction, we look at their methods, techniques, and crucially their character, from Polish double agent Roman Czerniawski, who played a major role in the Allied deception prior to the D-Day landings, to the infamous case of Kim Philby and the Cambridge Five and onto the more recent incredible story of former Al-Qaeda member turned MI6 spy Aimen Dean..The inside story of the secret world of espionage told first hand by the spies themselves. A look at the deadliest form of covert operation: the targeted elimination of the enemy.