David, the elder son of Tommy and Vi Adams, meets Kate Trimble, a cockney girl from Camberwell who has just arrived in Ashleigh with her aunt. Kate is imaginative and precocious, while David is happy-go-lucky , and as the war is directly affecting the lives of so many other members of the Adams family, Kate and David establish a friendship in the summer sunshine of Devon. But as their friendship develops some exciting undercurrents, an incident occurs which brings home to them the darker intrigues of wartime and provides a devastating shock to everyone.