We've long known what makes the spy novelist John le Carré write. Interviews over the years and Adam Sisman's excellent biography have provided the clues. Now we have it in his own words: a difficult childhood, a devotion to the classical German writers, a stint as a spy and brutal editing by his supervisors at MI5.Boyhood and the secret world stand out strongest.Le Carré (as David Cornwell) and his elder brother, Tony, were abandoned by their mother, Olive, when the boys were young. "In the creaking jargon of the secret world I later entered, her departure was a well-planned exfiltration operation," Le Carré writes in what is more random memoir than strict autobiography.He never felt any bitterness towards Olive, even after she'd left the boys in the care of their father, Ronnie, a crook, though not without charm, who beat him ("but only a few times and not with much conviction") and even tried to sue him for slander when the author was an adult, and wealthy.Emotional blackmail was not beneath Ronnie either. Imprisoned in Zurich for fraud, the father calls on the son for help: "I can't do any more prison, son," Ronnie tells him. "The sobs," writes Le Carré, "go through me like slow knives." His first attempt to deal with Ronnie was The Perfect Spy, an autobiographical fiction described by Philip Roth as the best English novel since the war and the first drafts of which Le Carré confesses "dripped with self-pity". In The Pigeon Tunnel it takes him until page 255 (out of 306) to write about Cornwell senior. "It took me a while to get on writing terms with Ronnie, conman, fantasist, occasional jailbird, and my father." He kind of forgives Ronnie: "Graham Greene [with whom he fell out over Le Carré's loathing for the KGB double agent Kim Philby] tells us that childhood is the credit balance of the writer. By that measure at least, I was born a millionaire."Ironically, Philby helped make Le Carré a literal millionaire. If The Spy Who Came in From the Cold made Le Carré's career, Tinker, Tailor, Soldier, Spy confirmed the writer's reputation. Le Carré admits that Philby was the "murky lamp that lit my path" in Tinker, Tailor, the book that gave new meaning to the word "mole".If Ronnie passed on to his son the gift of creating fiction (the father was a congenital liar), his first employers helped him craft his writing.No editor, he writes of those reading his secret reports, was so exacting, or so right. His debt of gratitude to the classically trained MI5 supervisors "for the most rigorous instruction in prose writing that I ever received" is one that "I can never sufficiently repay".The Pigeon Tunnel is an engaging story, of lunches with Margaret Thatcher and Rupert Murdoch, an abortive seduction at the age of 16 by an ambassador's wife who was "the most desirable woman I had ever seen" and of travelling, travelling, travelling, always to destinations where trouble - and a good angle - lurked. He doesn't reveal all, however. His marital infidelities are glossed over and Cornwell keeps his big secret: how he came up with the pen name John le Carré.The Pigeon Tunnel: Stories from My Life by John le Carré, published by Viking, R320..