A rollicking read for all those who enjoy a spy story so fanciful that Ian Fleming - himself an officer in Montagu's wartime department - would never have dared to invent it

Max Hastings, Sunday Times

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

Observer

Macintyre has a journalist's nose for a great story, and a novelist's skill in its narration ... Even more spellbinding than his previous story of wartime espionage, Agent Zigzag, with a cast-list every bit as dotty and colourful ... Macintyre is a master of the thumbnail character sketch

Mail on Sunday

With its fantastic plot and its cast of eccentric characters, the book reads like the most improbable of spy stories. It is a tribute to Macintyre's skill that we never for a moment forget that it is actually all true

Daily Telegraph

Astonishing ... Sheds riveting new light on this breathtaking plan

Daily Mail

Brilliant and almost absurdly entertaining

Malcolm Gladwell, New Yorker