In the event, had the party deliberately decided to bitch the cover plan, they could not have done it better. At about eight o’clock on the evening of 12 January, Addison Road (now Kensington Olympia) Station was closed, a police cordon kept pedestrians well out of sight of the station, the fleet of blacked-out cars duly arrived there and their occupants boarded the waiting special train.

Somewhere in Berkshire the train decanted them, and they boarded another fleet of cars which was waiting to drive them to the airfield. (The PM was driven the whole way by car.) On entering a village a mile or so from the airfield, some bright boy in the leading car of the convoy discovered that there was still three-quarters of an hour before the time set for takeoff. So he said to his companions, ‘Let’s pull up and have a drink at the village pub.’

Everyone being in holiday mood, his suggestion was immediately accepted. The entire convoy halted. Brooke, Portal, Mountbatten and a score of others, smothered with gold braid and their chests a sunset of medal ribbons, crowded into the little bar parlour. The publican, his eyes bulging at such a sight, hastily produced his very limited stock of hard liquor and they proceeded to drink the place dry. What a story he would have to tell his friends on the morrow, of the mighty warriors who had patronized his pub on their way to the airfield.

As soon as MI5 learned of this occurrence, they acted with great promptitude. They did not actually cast the unfortunate landlord into prison, but they placed him, his family and his staff under house arrest, put his pub out of bounds to the public for a month and set a guard on it to prevent any of its occupants telling others about the night when a gilded throng had made merry on the premises.

‘The Deception Planners’ p 116