Gaboriau was the first French novelist to write detective novels. His character Monsieur Lecog, private detective, first appeared in the novel, The Widow Lerouge as well as four other books. Baron Trigault's Vengeance is part of Gaboriau's novel in two parts. The novel begins: Vengeance! that is the first, the only thought, when a man finds himself victimized, when his honor and fortune, his present and future, are wrecked by a vile conspiracy! The torment he endures under such circumstances can only be alleviated by the prospect of inflicting them a hundredfold upon his persecutors. And nothing seems impossible at the first moment, when hatred surges in the brain, and the foam of anger rises to the lips; no obstacle seems insurmountable, or, rather, none are perceived.