The Pale Horse
Agatha Christie
 In the following summary, events are not given in strict narrative order. Mark Easterbrook, the hero of the book and its principal narrator, sees a fight between two girls in a Chelsea coffee-bar during which one pulls out some of the other's hair at the roots. Soon afterwards he learns that this second girl, Thomasina Tuckerton, has died. At dinner with a friend, Poppy Stirling mentions something called the Pale Horse that arranges deaths, but is suddenly scared at having mentioned it and will say no more. When Mark encounters the police surgeon, Corrigan, he learns of the list of names found in Father Gorman's shoe. The list includes the names of Mark's godmother, Lady Hesketh-Dubois, who has recently died of what appear to be natural causes, and of Thomasina Tuckerton. He begins to fear that the list contains the names of those dead or shortly to die. When Mark goes to Much Deeping with the famous mystery writer, Ariadne Oliver, to a village fete organised by his cousin, he learns of a house converted from an old inn called the Pale Horse, now inhabited by three modern "witches" led by Thyrza Grey. Visiting houses in the area, he meets a wheelchair-using man, Mr Venables, who has no apparent explanation for his substantial wealth. He also visits the Pale Horse, where Thyrza discusses with Mark the ability to kill at a distance, which she claims to have developed. In retrospect it seems to Mark that she has been outlining to him a service that she would be willing to provide. In the police investigation, there is a witness, Zachariah Osbourne, who describes a man seen following Father Gorman shortly before the murder. Later, he contacts the police to say that he has seen this same man in a wheelchair: it is Venables. When he learns that Venables suffered from polio and would be incapable of standing due to atrophy of the legs, Osbourne is nonetheless certain of his identification and begins to suggest ways that Venables could have faked his own disability. When Mark's girlfriend does not take his growing fears seriously, he becomes disaffected with her. He does, however, receive support from Ariadne Oliver, and from a vicar's wife (Mrs Dane Calthrop) who desires him to stop whatever evil may be taking place. He also makes an ally of Ginger Corrigan, a girl whom he has met in the area, and who successfully draws Poppy out about the Pale Horse organisation. She obtains from her an address in Birmingham where he meets Mr Bradley, a lawyer who outlines to him the means by which the Pale Horse can kill someone for him without breaking the law. With the agreement of Inspector Lejeune and the cooperation of Ginger, Mark agrees to solicit the murder of his first wife, who will be played by Ginger. At a ritual of some kind at the Pale Horse, Mark witnesses Thyrza apparently channel a malignant spirit through an electrical apparatus. Shortly afterwards, Ginger falls ill and begins to decline rapidly. In desperation, Mark turns to Poppy again, who now mentions a friend (Eileen Brandon) who resigned from a research organisation called CRC (Customers' Reactions Classified) that seems to be connected with the Pale Horse. When Mrs Brandon is interviewed, she reveals that both she and Mrs Davis worked for the organisation, which surveyed targeted people about what foods, cosmetics, and proprietary medicines they used. Mrs Oliver now contacts Mark with a key connection that she has made: another victim of the Pale Horse (Mary Delafontaine) has lost her hair during her illness. The same thing happened to Lady Hesketh-Dubois, and Thomasina's hair was easily pulled out during the fight. Moreover, Ginger has begun to shed her own hair. Mark recognises that these are symptoms, not of satanic assassination of some sort, but of thallium poisoning. At the end of the novel it is revealed that Osbourne has been the brains behind the Pale Horse organisation; the black-magic element was entirely a piece of misdirection on his part, while the murders were really committed by replacing products the victims had named in the CRC survey with poisoned ones. Osbourne's clumsy attempt to implicate Venables was his final mistake.