It was a heavenly summer, the summer in which France fell and the British Expeditionary Force was evacuated from Dunkirk. Leaves were never such an intense and iridescent green; sunlight glinted on flower-studded meadows as the Germans encircled the Maginot Line and overran not only France but Belgium and Holland. Birdsong filled the air in the lull between bursts of gunfire and accompanied the fleeing refugees who blocked the roads. It was as though the weather was preparing a glorious requiem for the death of Europe.