Private Enquiry agent Cyrus Barker has just about seen it all, until a Member of Parliament dies of poisoning during a consultation. Barker and his partner, Thomas Llewelyn soon learn that the same poisoned tarts also took out a family in the East End. In this 13th Victorian thriller (after Dance with Death), Barker and Llewelyn are hired by William Gladstone to find out who assassinated the House of Commons' newest member, but they soon find themselves the latest target of the Mad Pie Man.