Agatha Christie 
The Secret Adversary 

The Secret Adversary is a work of detective fiction by Agatha Christie and first published in the United Kingdom by The Bodley Head in January 1922 and in the United States by Dodd, Mead and Company later in that same year. The UK edition retailed at seven shillings and sixpence (7/6) and the US edition at $1.75 The story then moves forward four years to 1919 when a pair of friends, Tommy and Tuppence, set out to help a rich man find his long-missing cousin. The Secret Adversary is the second published detective fiction novel by British writer Agatha Christie, first published in January 1922 in the United Kingdom by The Bodley Head and in the United States by Dodd, Mead and Company later in that same year.