The unnamed narrator is discussing  some of his most celebrated cases  with with the famous Parisian amateur detective C. Auguste Dupin when they are joined by the Prefect of the Police, a man known as G—. The Prefect has a case he would like to discuss with Dupin. A letter has been stolen from the boudoir of an unnamed female by the unscrupulous Minister D—. It is said to contain compromising information. Danton was in the room, saw the letter, and switched it for a letter of no importance. He has been blackmailing his victim.