"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 1] and in the United States by Dodd, Mead and Company later in that same year. 2] 3] The UK edition retailed at seven shillings and sixpence (7/6) 1] and the US edition at $1.75. 3]The book introduces the characters of Tommy and Tuppence who feature in three other Christie...