The story takes place during the 1930s, a time of totalitarian reign in Mexico. It is set south of Mexico City in the province of Tabasco. In his introduction to the 1962 edition of the book, Greene explains that he traveled in Mexico from 1937 to 1938 for the express purpose of writing a novel. Greene relates that the towns he visited are depicted in the novel: El Frontera, where the story opens; Tabasco, a prohibitionist town; Villahermosa, where he developed the character of the priest and discovered the prototype for the lieutenant; and Las Casas, where churches still stood although no priest was allowed to enter them.