‘If you get out now, Gnädige Frau, you can take the underground and you will be in the city in no time,’ said a fellow traveller to Christabel Bielenberg on a stationary train just outside Berlin in 1944. So she did and the train steamed off. A few miles on, American bombers attacked, killing almost everyone on board. Her life had been saved by luck – and the kindness of a stranger. It’s the stories of such small human decencies in the midst of war that make her memoir The Past Is Myself (1968) such an extraordinary book.