Mr Rankin promises us a ride into the secret world of deception, camouflage, secret agents and misdirection that helped Britain in two world wars. And indeed we do get that. That bit takes up about half of the book. The other half is excerpts from people's diaries, essays about the war, Churchill's political career, bits snipped out of his family history, bit more about the war that doesn't actually have anything to do with deception, camouflage, secret agents and misdirection. Padding, really. When I picked the book up, I thought, "Wow, this will be fascinating". But there's an awful lot of pages to get through. So some judicious editing could have turned this into a very lean 250/300 pages.
That said, when you do get to the deception, camouflage etc etc, you fly through them. It's cracking stuff. Some is very Boys Own, some almost unbelieveably dotty British eccentricity and, above all, huge amounts of resourcefulness, imagination and bravery. The stories are incredible. And you realise how much the success of D Day depended on some wooden tanks and landing craft of a fictional US Army Group in Kent.
So it's worth a read, all the more so if you're willing to skip bits.