Spy and detective novels have a common goal: to thrill. In murder mysteries or shilling shockers, the thrill depends on criminal culpability and the investigation of wrongdoing. Once the thriller raises suspicion, evidence establishes guilt or innocence. Having proven guilt, the thriller arbitrates the punishment of crimes. The classic British detective novel, as written by Dorothy Sayers and Agatha Christie, begins with a murder and ends with the explanation of motive and method of the crime. The classic British spy story, as written by John Buchan and John le Carré, begins with the recruitment of an ordinary fellow into a conspiracy that endangers the life of the protagonist. Both spy and detective novels are compelled by human curiosity, a will to know, even if knowledge entails physical jeopardy. The detective assembles clues until a coherent story emerges; the secret agent construes codes to verify that a conspiracy exists. In all instances, the thriller adopts a stance toward citizenship, social responsibility, and justice.

Both detective and spy novels originate in nineteenth-century fiction. Charles Dickens shadowed the London police and wrote about his experiences in Household Words. In Bleak House (1853) Dickens documents constabulary techniques in the figure of Inspector Bucket. In Wilkie Collins's The Moonstone (1868) Sergeant Cuff investigates the theft of a diamond stolen from a shrine in India. These characters institutionalize curiosity and its thrills within police procedure.