It turns out that the ill-fated Operation Jubilee, in August 1942—an amphibious assault on this Nazi-occupied French town during which more than half of the 6,000-plus Allied troops were killed, wounded, or taken prisoner within 10 hours—was just a bit of sleight-of-hand misdirection designed to cover a secret mission directed by Lord Mountbatten and a young naval-intelligence officer, the pre–James Bond Ian Fleming. According to The Guardian, Leah Garrett, in her new book, X-Troop: The Secret Jewish Commandos of World War II, describes how the attack was intended to draw attention while the British government deployed an elite group of five trained, interned German refugees dressed in military uniforms “on a secret cloak-and-dagger mission to occupied Dieppe to snatch an Enigma coding machine from under the Nazis’ noses.” (The Enigma was a mid-20th-century alphabet-scrambling cipher machine that the Nazis, who mistakenly considered it infallible, depended on to send top-secret messages.)

The newspaper reports that “Garrett unearthed a long-classified, after-action report written by one of the Sudeten Germans, known by his Anglicised name Maurice Latimer, who said his orders were ‘to proceed immediately to German General HQ in Dieppe to pick up all documents, etc of value, including, if possible, a new German respirator’”—presumably a reference to the Enigma, an earlier version of which had already been partly decrypted by the Bletchley Park code breakers. The clandestine operation failed, however: one of Latimer’s colleagues was killed, one seriously injured, and two captured. And this particular Enigma, at any rate, remained just that, an enigma.