John Mallathorpe, a wealthy Yorkshire industrialist and land owner dies in an accident, apparently without making a will. His estate goes to his wife and two children and they live the good life for a number of years. However, an old bookseller, whilst clearing some old books passed on from the Mallathorpe estate, finds a copy of Mallathorpe's will inside one of the books, and unfortunately for the family the will bequeaths the whole estate minus a small endowment for the family, to the city authorities. The bookseller takes the will to the local solicitor to seek advice, but unfortunately dies in the solicitor's office. The clerk on duty sees an opportunity to benefit himself from the knowledge of the existence of the will. This is a gripping detective story, with many twists and turns, based in Edwardian England.