Leavitt, the author of several novels and short-story collections with gay protagonists, rings the gay-martyr theme in the book’s opening pages by invoking another film classic, “The Man in the White Suit.” In that 1951 comedy, which Leavitt reads as a gay allegory, a scientist is chased by a mob that feels threatened by a miraculous invention of his. The possibility of clandestine assassination is hinted by the title of David Leavitt’s short biography, “The Man Who Knew Too Much: Alan Turing and the Invention of the Computer” (Norton/Atlas $22.95), borrowed from the Hitchcock thriller. No one tested the apple found by his bedside for cyanide. The coroner at his inquest knew none of this.

He began travelling abroad in search of sex, visiting countries bordering on the Eastern bloc. After his conviction for homosexuality, he may have seemed out of control.

The flight to Moscow, in 1951, of Guy Burgess and Donald Maclean, British diplomats and rumored lovers who had been covertly working for the Soviets, prompted one London newspaper to editorialize that Britain should adopt the American policy of “weeding out both sexual and political perverts.” Turing’s role in wartime code-breaking had left him with an intimate knowledge of British intelligence. But it is also tempting to speculate about whether he really was a suicide. It is natural to view Turing as a gay martyr, hounded to death for his sexuality despite his great service to humanity. And it wasn’t until the eighties that Turing got the credit he deserved for a second, and equally formidable, achievement: creating the blueprint for the modern computer. But the existence of the British code-breaking effort remained closely guarded even after the end of the war the relevant documents weren’t declassified until the nineteen-seventies. Had this been publicly known, he would have been acclaimed a national hero. It was Turing who was chiefly responsible for breaking the German Enigma code during the Second World War, an achievement that helped save Britain from defeat in the dark days of 1941. Another, however, had not yet come to light. One of his secrets had been exposed two years before his death, when he was convicted of “gross indecency” for having a homosexual affair. Turing was, by necessity rather than by inclination, a man of secrets. At an inquest, a few days later, his death was ruled a suicide. Before getting into bed the night before, he had taken a few bites out of an apple that was, apparently, laced with cyanide. On June 8, 1954, Alan Turing, a forty-one-year-old research scientist at Manchester University, was found dead by his housekeeper.

Turing enigma book