A new series of five programmes using documentary evidence to throw new light on past events.

Helen Weinstein meets Vasili Mitrokhin, the man who was once in charge of the KGB's most secret documents. He tells the story of how he changed from being a loyal KGB bureaucrat to a covert and compulsive noter of the files that crossed his desk. This extraordinary hoard was eventually brought to Britain when Mitrokhin defected and became the source of newspaper stories of granny spies and Romeo policemen. Weinstein explores the nature of the man and the journey he and his notebooks have taken.