Emile Gaboriau (1832–1873) is one of the founders of the detective genre, whose works became the basis for many subsequent authors. His very first novel, The Lerouge Affair (1866), caused a great stir by introducing the public to a new type of hero – a clever, insightful detective, in whom society saw a kind of "guardian angel". This is exactly the character that became his famous police inspector Lecoq, the predecessor of Sherlock Holmes. Arthur Conan Doyle acknowledged the influence of Gaboriau, and Edgar Wallace and many other authors drew inspiration from his detective constructions.

This volume presents the novel Lecoq, Agent of the Detective Police, which begins with a mysterious crime: three men are murdered in the Parisian tavern "Pepperbox". Two women, who became involuntary witnesses, disappear before the police arrive, and the killer… surrenders without resistance, although he could have easily escaped. Why did he voluntarily surrender himself to justice? What are his true motives? The answers are hidden in a clever investigation that will lead the reader step by step through a tangle of secrets, intrigues and unexpected solutions.