Sidney Grice, of 125 Gower Street, is London's premier personal detective. But since his last case led an innocent man to the gallows, business has been light. Listless and depressed, Grice has taken to lying in the bath for hours. Once a voracious reader, he will pick up neither book nor newspaper. His ward, March Middleton, has been left to dine alone. Then an eccentric member of a Final Death Society has the temerity to die on his study floor. Finally Sidney Grice and March Middleton have an investigation to mount - an investigation that will draw them to an eerie house in Kew, and the mysterious Baroness Foskett.