Jean Wildacre is killed on stage during a magic show. She was a member of an occult group headed by imperious Ernest Balliol.Balliol and a former colleague in the group Aloysius Wilmington have long been at odds as both are anxious to locate a priceless antique book,believed to be somewhere on Aloysius's premises. Balliol has married again and his daughter Isolde is as fervent as he is in trying to find the book. His gentler son Tristan lives with and cares for his mother,Ernest's fragile first wife Rosemary. Two more deaths follow and each victim was present when one of Balliol's wives was recruited into the group years earlier. Suspicion falls on Ernest and his children and on Simon Wilmington,actually the illegitimate son of Aloysius,though he has been led to believe he is the magician's nephew.