Tommy and Tuppence Beresford are called to duty at an international detective agency. On assignment, they are told to be wary of the number sixteen. If they see it in writing or hear it in conversation with a stranger, that means they are close to finding the spy ring they seek.
Agatha Christie is the most widely published author of all time, outsold only by the Bible and Shakespeare. Her books have sold more than a billion copies in English and another billion in a hundred foreign languages. She died in 1976, after a prolific career spanning six decades.