London 1915 and Britain is at war with Germany. Stylish lady detective, Miss Isabel Hewitt, has agreed to play the piano at a fund raising concert. The funds are for a small military hospital where her former manservant, Clarke, works as an orderly. But her rehearsal is interrupted when a Mrs Peveril calls to ask her to investigate the death of her daughter Leah. The police think it is suicide, the mother hopes it is not. Isabel agrees to take on the case, but soon discovers the girl was leading a double life. Is it suicide or murder?