Just down from Cambridge in the summer of 1937, Sally Marsden contemplates her future without enthusiasm. So many have assumed she will marry Hugh Jerrold it is, practically, an engagement. When Hugh returns from his diplomatic posting to China they will be married. But before submitting to the strictures of upper-middle-class life, Sally embarks on one last adventure - travelling to China herself, where she will spend the winter. The Sino-Japanese war begins shortly after Sally's arrival and a disastrous miscalculation separates her from Hugh and leaves her trapped in Nanking, one of two dozen Europeans and Americans to witness the capture and sack of the city by the Japanese Imperial Army. The experience is shared with Peter Moss, an American photo-journalist and friend of Hugh. Bystanders in a racial war, Sally and Peter emerge physically unscathed but utterly changed, and all their attempts to carry on as before quickly founder.