The Secret Adversary

By Agatha Christie.

Tommy and Tuppence, two young people short of money and restless for excitement, embark on a daring business scheme – Young Adventurers Ltd.. Their advertisement says they are ‘willing to do anything, go anywhere’. But their first assignment, for the sinister Mr Whittington, plunges them into more danger than they ever imagined .

NY. Harrow and Heston Classic Reprint. (1922) 249 pages.