Dame Agatha Mary Clarissa Christie, (1890 – 1976) is possibly the world's best-known mystery writer. The Guinness Book of Records listed her as the best-selling fiction author of all time with over two billion copies in the English language and in over 45 foreign languages, and most of her books and short stories have been filmed.

Her play The Mousetrap (opened in 1952) is the longest continuously running play in theatrical history – it still runs today after more than 20,000 performances.

Agatha Christie was meticulous in "playing fair" with the reader by giving all the information for solving the puzzle.

According to Times Online, the study conducted by neuro-linguists at the universities of London, Birmingham and Warwick shows that Agatha Christie peppered her prose with words and phrases that act as a trigger to raise levels of serotonin and endorphins, the chemical messengers in the brain that induce pleasure and satisfaction. Such words include she, yes, girl, kind, smiled and suddenly. Common phrases include "can you keep an eye on this", "more or less", "a day or two" and "something like that".

Agatha Christie also wrote six romantic novels under the pseudonym Mary Westmacott.

Official Agatha Christie site