Christabel Strange, a highly successful young novelist, is taken ill and dies a year before the story begins. It was her wish that her biography should be written by her friend Marcia Wentworth; but inexplicably, she bequeathed her diaries to her wily, eccentric grandmother, who loathes Marcia and refuses to allow her to see them. Dr. George Cardew, Christabel's childhood friend, arriving at the house (which according to Christabel's will, is being shared by Marcia), finds himself between opposing and bitterly hostile camps, for the family are at loggerheads with Marcia. He begins to wonder why Christabel behaved in such a peculiar way, and whether her death was really due to a fever. The possibility of foul play becomes a certainty when another murder takes place and a volume of the diary is stolen. Gradually Dr. Cardew pieces together the clues to Christabel's hidden life, but it is not until there has been further violence that he is able to identify the murderer and the reason for the original crime.