Tommy and Tuppence Beresford are the protagonists of a series of novels and short stories by Agatha Christie, and mark the few ventures that Christie made into espionage tales rather than the whodunits she's known for. 'The Secret Adversary' introduces Tommy and Tuppence who feature in three other Christie novels and one collection of short stories; the five Tommy and Tuppence books span Agatha Christie's writing career. Thomas Beresford and Prudence "Tuppence" Cowley started out as friends in post-World War I Britain. Jobless and penniless, they place an ad in the paper marketing themselves as adventurers, leading to an encounter that starts their career as spies for an unnamed British intelligence agency. Interestingly, the dedications of two Tommy and Tuppence books ('The Secret Adversary' and 'By the Pricking of My Thumbs') are the only times Christie ever dedicated a book directly to her readers. The Tommy and Tuppence books are: 'The Secret Adversary' (1922); 'Partners in Crime' (short story collection) (1929) 'N or M?' (1941) 'By the Pricking of My Thumbs' (1968) 'Postern of Fate' (1973) Upon publication of the first book edition it was reviewed by The Times Literary Supplement in its edition of 26 January, 1922, which described it as "a whirl of thrilling adventures." The critic for The New York Times Book Review (11 June 1922) was also impressed: "It is safe to assert that unless the reader peers into the last chapter or so of the tale, he will not know who this secret adversary is until the author chooses to reveal him." The review gave something of a backhanded compliment when it said that Christie "gives a sense of plausibility to the most preposterous situations and developments." Robert Barnard described the novel as "The first and best (no extravagant compliment this) of the Tommy and Tuppence stories. It tells how the dauntless pair foils a plot to foment labour unrest and red revolution in Britain, masterminded by the man behind the Bolshevists. Good reactionary fun, if you're in that mood." Some additional blurbs regarding the book, and used by The Bodley Head for advertising subsequent print runs, are as follows: "It's an excellent yarn and the reader will find it as impossible as we did to put it aside until the mystery has been fathomed." - Daily Chronicle "We promise our readers an exciting story of adventure, full of hairbreadth escapes, and many disappointments if they try to guess the riddle before the author is ready to give them the clue. An excellent story." - Saturday Review. "The atmosphere of the book is admirable and the story will be read with avidity by all. Undoubtedly the book is a success." - East Anglian Daily Times. "A book of thrilling adventure. Sensational adventures which make thrilling and gripping reading. Mrs Christie has certainly succeeded in writing a story not only entertaining, but ingenious and amazingly clever." - Irish Independent. Like its predecessor, 'The Mysterious Affair at Styles, ' 'The Secret Adversary' was first published as a serialization in The Times weekly edition (aka The Weekly Times) as a complete and unabridged text in seventeen installments from 12 August (Issue 2328) to 2 December 1921 (Issue 2343). Christie was paid 50 for the serialization rights ( 1,545 in 2003 currency).