“Christie had a … partiality to murderous medical people who have both the specialized knowledge and the opportunity to administer such lethal agents.”1 This partiality persisted throughout her 101 short stories and novels. In her first book, The Mysterious Affair at Styles, a doctor tries to cover up a murder. In her first play, Black Coffee , a doctor is the prime murder suspect. And in her last book, The Postern of Fate, a doctor is one of the two murderers. Where the occupation of the murderer is known, doctors make up the largest group (table⇓). View this table: Frequency of murderers’ occupations in Agatha Christie’s 101 novels and short stories In Christie’s most famous thriller, The Murder of Roger Ackroyd , Dr James Sheppard is the culprit and her choice of a doctor murderer may have been influenced by the real life poisoning of Charles Bravo, who Christie believed was killed by Dr James Manby Gully, the lover of Bravo’s wife. In Cards on the Table Dr Roberts murders not only his lover’s wife, by poisoning her travel immunisation typhoid injection, but he also kills a rich man in whom she confides, by putting anthrax on his shaving brush. Roberts’s other victims included witnesses to his crimes, who are injected by him with the anaesthetic Evipan, falsely described as “a simple restorative,” and the doctor comments that he has “always been interested in crime. Bad thing for a doctor, perhaps mustn’t say so to my nervous patients!” Another quadruple serial killer was the GP in The Pale Horse , who murders his patients with morphine. Dr Anderson, in The Flock of Geryon , one of the books in the short story collection The Labours of Hercules , in which Poirot feels he must destroy various monsters, is a crazy …