The Secret Adversary is a work of detective fiction

Detective fiction

Detective fiction is a sub-genre of crime fiction and mystery fiction in which an investigator , either professional or amateur, investigates a crime, often murder.-In ancient literature:...

 by Agatha Christie

Agatha Christie

Dame Agatha Christie DBE was a British crime writer of novels, short stories, and plays. She also wrote romances under the name Mary Westmacott, but she is best remembered for her 66 detective novels and 14 short story collections , and her successful West End plays.According to...

 and first published in the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 by The Bodley Head

The Bodley Head

The Bodley Head is an English publishing house, founded in 1887 and existing as an independent entity until the 1970s. The name has been used as an imprint of Random House Children's Books since 1987...

 in January 1922 and in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 by Dodd, Mead and Company

Dodd, Mead and Company

Dodd, Mead and Company was one of the pioneer publishing houses of the United States, based in New York City. Under several names, the firm operated from 1839 until 1990. Its history properly began in 1870, with the retirement of its founder, Moses Woodruff Dodd. Control passed to his son Frank...

 later in that same year. The UK edition retailed at seven shillings and sixpence

British sixpence coin

The sixpence, known colloquially as the tanner, or half-shilling, was a British pre-decimal coin, worth six pence, or 1/40th of a pound sterling....

 (7/6) and the US edition at $

Dollar sign

The dollar or peso sign is a symbol primarily used to indicate the various peso and dollar units of currency around the world.- Origin :...

1.75. The book introduces the characters of Tommy and Tuppence

Tommy and Tuppence

Tommy and Tuppence are two fictional detectives, recurring characters in the work of Agatha Christie. Their full names are Thomas Beresford and Prudence Cowley....

 who feature in three other Christie books and one collection of short stories written throughout her writing career.
Set in 1919 London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 and various other outlying locales throughout Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

, 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 … [w]illing to do anything, go anywhere … [n]o unreasonable offer refused." Being overheard by Mr.