Seeking excitement in the wake of the Great War, Tommy and Tuppence Beresford accept the management of a detective agency, plunging them into a series of high-stakes investigations. The duo must navigate a landscape of deception and criminal intrigue, utilizing their wits to solve cases that range from missing jewelry to complex homicides. Their objective is to prove their competence as investigators while maintaining their partnership amidst the pressures of their new profession. The narrative unfolds through a collection of interconnected short stories, each presenting a distinct puzzle that tests their deductive capabilities and their ability to operate under the guise of professional detectives.

This collection is widely recognized as a lighthearted departure from the author's more somber detective novels, emphasizing wit and stylistic experimentation. Readers often highlight the charm of the central duo, whose evolving relationship provides a consistent emotional anchor throughout the varied cases. The work is frequently noted for its clever subversion of contemporary mystery conventions, demonstrating the author's versatility beyond her more famous series. The episodic nature of the stories allows for a brisk, engaging pace that maintains interest without the weight of a singular, long-form mystery.