Her four children have flown, her husband is otherwise occupied, and after twenty years of being a good wife and mother, Kate Brown is free for a summer of adventure. She plunges into an affair with a younger man, travelling abroad with him, and, on her return to England, meets an extraordinary young woman whose charm and freedom of spirit encourages Kate in her own liberation. Kate's new life has brought her a strange unhappiness, but as the summer months unfold, a darker, disquieting journey begins, devastating in its consequences.