The answer, revealed by villainous monologue, is that the supposedly innocuous shopkeeper Zachariah Osbourne (Bertie Carvel) has a mail-order murder business where he seeks out the greedy and removes “obstacles” from their lives using the untraceable poison thallium. But as these victims’ hair starts falling out and they appear to die of natural causes, the question remains: what is the connection, and who is behind it? Further, though Mark tells Inspector Lejeune (Sean Pertwee) that there is no connection with other names on the list (save one nephew), we know otherwise. Game on! But it’s very quickly apparent that most of the people whose names on the list are already dead, and there are more deaths to come. The two-part miniseries takes place in 1960s London and focuses on the character of Mark Easterbrook (Rufus Sewell), who finds out his name is on a list discovered in a dead woman’s shoe.

The Pale Horse, now available on Amazon Prime, is no different-but your mileage may vary on whether or not you think those changes are a positive. In each, Phelps has updated the material (if not the setting) to often land on a different killer from Christie’s source material, or to come about the revelation in a new way.

A doctor conferring with Scotland Yard had read The Pale Horse and realised that the mysterious 'Bovingdon bug' was actually thallium poisoning.The Pale Horse is the latest in a quintet of Agatha Christie adaptations by Sarah Phelps, including The Witness for the Prosecution, And Then There Were None, and Ordeal by Innocence.

In another instance, in 1971, a serial killer, Graham Frederick Young, who had poisoned several people, three fatally, was caught thanks to this book. In 1975, Christie received a letter from a woman in Latin America who had thus saved a woman from slow poisoning by her husband and in 1977, a nurse who had been reading The Pale Horse correctly suggested that a baby in her care was suffering from thallium poisoning. This novel is notable among Christie's books as it is credited with having saved at least two lives after readers recognised the symptoms of thallium poisoning from the description in the book. The other reintroduced Christie's earlier thoughts about 'Voodoo etc., White Cocks, Arsenic? Childish stuff - work on the mind and what can the law do to you? Love Potions and Death Potions, - the aphrodisiac and the cup of poison. One, a book 'would start somehow with a list of names. The Pale Horse combined two ideas that Agatha Christie had been considering.

The pale horse marple