Purloined Letter

Of all of Poe's stories of ratiocination (or detective stories), "The Purloined Letter" is considered his finest. This is partially due to the fact that there are no gothic elements, such as the gruesome descriptions of dead bodies, as there was in "The Murders in the Rue Morgue." But more important, this is the story that employs most effectively the principle of ratiocination; this story brilliantly illustrates the concept of the intuitive intellect at work as it solves a problem logically. Finally, more than with most of his stories, this one is told with utmost economy.
"The Purloined Letter" emphasizes several devices from "The Murders in the Rue Morgue" and adds several others. The story is divided into two parts. In the first part, Monsieur G —— , Prefect of Police in Paris, visits Dupin with a problem: A letter has been stolen and is being used to blackmail the person from whom it was stolen. The thief is known (Minister D —— ) and the method is known (substitution viewed by the victim, who dared not protest). The problem is to retrieve the letter, since the writer and the victim, as well as Minister D —— , have important posts in the government; the demands he is making are becoming dangerous politically. The Prefect has searched Minister D —— 's home thoroughly, even taking the furniture apart; he and his men have found nothing. Dupin's advice is that they thoroughly re-search the house. A month later, Monsieur G —— returns, having found nothing. This time, he says that he will pay fifty thousand francs to anyone who can obtain the letter for him. Dupin invites him to write the check; when this is done, Dupin hands the Prefect the letter without any further comment.
The second half of "The Purloined Letter" consists of Dupin's explanation, to his chronicler, of how he obtained the letter. One of his basic assumptions is an inversion of one of the aphorisms that was introduced in "The Murders in the Rue Morgue"; the case is so difficult to solve because