The real danger to the UK in 1940 was not of a German invasion from without, but of the peace makers from within. If Fighter Command had lost the Battle of Britain and the Luftwaffe had been allowed to go about its business in our skies by day as well as by night then that would have been the moment for them to show their hands. As it was they remained in the shadows until that last chance saloon in May 1941 at Dungavel House, home of the 14th Duke of Hamilton, Air Commodore Douglas Douglas-Hamilton, who was on duty that night at RAF Turnhouse with responsibility for Scotland's air defence. The lights went on at the Dungavel Airstrip but then 15 minutes later went out again. The party slunk back into the shadows, and Churchill was able to enjoy watching a screening of the Marx Brothers at Downing Street...