Having spent the past few decades obsessed with Hitler, the publishing industry has of late realised that the many untold stories from the Allied side of the war, from Bletchey Park on, are equally enthralling, disturbing and near-fantastical. The Times's associate editor, Ben Macintyre, also the author of the acclaimed Agent Zigzag, is fast becoming a one-man industry in these updated tales of cunning, bravery and skulduggery. With his mix of meticulous research and a good hack's eye for narrative, it is hard to think of a better guide to keep beckoning us back to that fascinating world.

This is not an untold story. The tale of the transformation of an "unknown" corpse into the fictitious Captain William Martin  whose body, complete with an entirely invented past life (theatre stubs, love letters) and, crucially, misleading information on the forthcoming invasion of Sicily, was deployed, apparently drowned, into the sea off Spain in 1943 as a "Trojan horse" to find its way back to German intelligence  was the basis of the 1956 film The Man Who Never Was. But as with so many films and books in the two decades following the war, propagandising and officialdom prevented the entire story from coming to light: Macintyre, by means of extensive sleuthing  there are more than 30 pages of impeccable annotated notes  and a fortuitous visit to the son of intelligence officer Ewen Montagu, one of the main players possessed of the necessary "corkscrew mind", gives the final word on this extraordinary episode.

It was, ultimately, a success. Hitler was persuaded that the Mediterranean offensive would come at Greece and Sardinia, and any attack on Sicily would be a feint. His defences were radically, disastrously shifted and the rest is history. Part of the story here, as it was with Normandy, is of the abject failures of German intelligence. They were not stupid people but, as would also happen the next year with D-day, the crucial flaw was their (justifiable) fear that any intelligent scepticism, once their Führer had become convinced one way or another, would result in blistering rage, exile or worse.

But a huge part of the story, of course, is of the strange men, and the strange world they inhabited, behind the planning. There was ego and rivalry and brilliance aplenty in Whitehall in those days, from Montagu and the oddball Charles Cholmondeley and the smattering of novelists, Ian Fleming included, brought often from civilian life to plot, to imagine, to deceive: egos that might have imploded were it not for the constant shared enemy. They had a lot of luck in the end; a thousand tiny things could have gone wrong. But they also displayed uncanny adroitness, not just in the selling of deception but in its after-sales care.

In the story of the homeless Welsh vagrant, Glyndwr Michael, whose body proved so much more worthwhile in death than in life, there is enough pathos and tragedy to remind you that you're reading real life-or-death stuff, influencing the outcome of the entire war, rather than enjoying a rollicking novel, rollicking though the book often is. There's romance, and glamour, and even the splendidly named Sir Bentley Purchase, the cheerfully black-humoured coroner of St Pancras who (illegally) colluded in the procurement of the body. It's hard not to feel, sometimes, that you are reading of impossibly distant times, when men, even dead men, were real men, rather than overgrown toddlers. Then you come on some tiny telling detail, as on page 187, when Montagu and Cholmondeley took two office secretaries to the theatre, still maintaining the solemn pretence of mourning their "friend", the drowned Captain Martin, even as the tramp Michael's body was being lifted from the water off Punta Umbria by a Spanish fisherman. On the bill that night, Macintyre has brilliantly elected to find out and inform us, were two unknown teenagers named Eric Morecambe and Ernie Wise. The shock is not that this all happened, but that it wasn't so very long ago.