The romantic story of David Robertson, among the islands off and on the coast of Maine

There are 60 pages of Notebook showing its origins, and thanks to these we can see the detailed working-out that went into one of Christie’s most ingenious novels. The setting exists in reality as Burgh Island, off the coast of Devon, a venue well known to Christie as she stayed at the hotel there on a few occasions. The island is cut off from the mainland twice a day at high tide and is reached by a sea-tractor. She utilises its geography to suit her purposes in creating a perfect alibi. That storehouse of plot devices, The Thirteen Problems, yet again provided the rough basis for this novel. вЂA Christmas Tragedy’ features two people, the murderer and a witness (in this case Miss Marple herself), вЂfinding’ a dead body before it has been murdered, thereby providing the killer with an impeccable alibi. In the case of the short story the body is that of a natural death victim, conveniently dead two hours earlier, but in the novel it is the live body of the killer’s accomplice. Both plots feature a large and camouflaging hat (also a feature of Dead Man’s Folly) ...»