A cleric, a lawyer, and a psychiatrist find themselves together on a train bound for Newcastle. There is a fourth man in the compartment, who apparently pays no attention to his companions' animated conversation. But do they have something to learn from this stranger?
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.