The Secret Adversary

Set in 1919 London and various other outlying locales throughout Britain, young couple Tommy Beresford and Prudence "Tuppence" Cowley, out of work and money, form the "The Young Adventurers, Ltd." planning to hiring themselves out as "adventurers … willing to do anything, go anywhere … no unreasonable offer refused." Being overheard by Mr. Whittington, Tuppence is offered a comfortable position, only to be rejected after she gives her name as "Jane Finn", a name Tommy overheard when he and Tuppence earlier entered Lyons for tea and a bite and were walking to their table ("funny scraps one does overhear"). Lyons was the same restaurant at which Whittington overheard Tommy and Tuppence's plan for their new "joint venture." Whittington becomes suspicious of Tuppence, believing her to be blackmailing him.