The friendship between Graham Greene and Kim Philby is one of the most mysterious of the twentieth century. Greene, the internationally lauded novelist who wrestled with the themes of faith and betrayal in his work. Philby, the British intelligence-officer-turned-spy for the Soviets, and one of the most reviled men of his era. The two men met as young MI6 officers in war-torn London, working together to defeat the Nazis.

But after Greene suddenly resigned just days before D-Day, questions started to arise. He turned back to literature, using his experience in the intelligence services as a backdrop for his novel Our Man in Havana and the screenplay of The Third Man. Lurking within the pages lay suspicions of his friend, with characters and plots echoing Philby's life. Was Philby the real 'third man'? Did Greene's work contain coded messages and warnings of betrayal to M16?

In this revelatory book, bestselling author Robert Verkaik chronicles the relationship of these two giants of the 20th century, spanning the defeat of Nazism and the end of the Cold War, right up until Philby's death in 1988. This is more than just a riveting tale of espionage; it is the story of an unusual friendship that survived against all odds. Ultimately, The Writer and the Traitor explores the perplexing question that nobody yet has answered: why did Graham Greene remain loyal to Britain's most hated traitor?

Robert Verkaik is an author and award-winning journalist. He was the Home Affairs Editor of the Independent and the Security Editor of the Mail on Sunday. He is the author of Defiant: The Untold Story of the Battle of Britain, Posh Boys and Jihadi John: Making of a Terrorist, as well as the Sunday Times bestseller The Traitor of Colditz, and The Traitor of Arnhem. He is a non-practising barrister and lives in Surrey.