Harry Chapman Pincher is regarded as one of the finest investigative reporters of the twentieth century. Over the course of a glittering six-decade career, he became notorious as a relentless investigator of spies and their secret trade, proving to be a constant thorn in the side of the establishment. So influential was he that Prime Minister Harold Macmillan once asked, 'Can nothing be done to suppress Mr Chapman Pincher?' It is for his sensational 1981 book, Their Trade is Treachery, that he is perhaps best known. In this extraordinary volume he dissected the Soviet Union's inflitration of the western world and helped unmask the Cambridge Five. He also outlined his suspicions that former MI5 chief Roger Hollis was in fact a super spy at the heart of a ring of double agents poisoning the secret intelligence service from within. However, the Hollis revelation was just one of the book's many astounding coups. Its impact at the time was immense and highly controversial, sending ripples t