Kim Philby is the most famous double agent in history. But a quarter of a century after his death, he has become a caricature, the gentleman master spy. The real Kim Philby was a man of contradictions. He was charming and courteous, but he was also a fanatic and a ruthless killer, who deceived everyone around him. In this two-part series, bestselling author Ben Macintyre explores the man behind the myth. He argues that the key to Philby’s success, and his survival, lay in his friendship with a man that history has largely forgotten - Nicholas Elliott. Elliott was Philby’s colleague in MI6 who befriended him, defended him, and unwittingly supplied him with secrets... until he discovered the truth. Ben Macintyre tells this extraordinary story of espionage, murder and intimate betrayal and visits the locations where the action took place: London, Istanbul, Washington DC, Beirut and Moscow. This is the remarkable tale of two friends and two spies, each working on opposite sides in the Cold War.