The Mysterious Affair at Styles

Agatha Christie's first novel, The Mysterious Affair at Styles was the result of a dare her sister Madge made to write a story.  The book features World War I soldier Hastings, who is sent back to England to recover from an injury at the Styles Court owned by his friend John Cavendish.  He meets John's new stepmother, Mrs. Inglethorpe, a rich heiress who later turns up murdered.  An old friend, Belgian detective Hercule Poirot, is hired to track down the murderer.  It was the Belgian refugees from the First World War who settled in Christie's home town of Torquay, England who inspired her to create the character Poirot.  

Note:  Christie called her first house "Styles" after her first book, published in 1920 http://www.agathachristie.com/stories/the-mysterious-affair-at-styles.

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