Thirteen guests arrived at dinner at the actor's house. It was to be a particularly unlucky evening for the mild-mannered Reverend Stephen Babbington, who choked on his cocktail, went into convulsions and died.

But when his martini glass was sent for chemical analysis, there was no trace of poison � just as Poirot had predicted. Even more troubling for the great detective, there was absolutely no motive�

Agatha Christie was born in Torquay in 1890 and became, quite simply, the best-selling novelist in history. Her first novel, The Mysterious Affair at Styles, written towards the end of the First World War, introduced us to Hercule Poirot, who was to become the most popular detective in crime fiction since Sherlock Holmes. She is known throughout the world as the Queen of Crime. Her books have sold over a billion copies in the English language and another billion in over 100 foreign languages. She is the author of 80 crime novels and short story collections, 19 plays, and six novels under the name of Mary Westmacott.