The short story "The Purloined Letter" by Edgar Allan Poe features C. Auguste Dupin, who also appears in other mystery stories by Poe. Although he is not a professional detective, he enjoys using his intellect and imagination to solve intriguing puzzles. In the first part of the story, he and the unnamed narrator are smoking together one evening when the prefect of the Paris police arrives and explains the troubling theft of a compromising letter. He and his men know who took it and the place where it is hidden, but despite a meticulous search, he has been unable to recover it.

In the second part, Dupin reveals that he has found the letter to the prefect. After the prefect leaves, Dupin explains to the narrator the intellectual process he went through that led him to find and recover it.

Poe is known for the dark, gothic tone of his horror stories, but "The Purloined Letter" has a completely different tone. Nothing in it is frightening or dangerous. Instead, it is entertaining as an intellectual puzzle. Poe's tone in this story can be described as casual, clever, light-hearted, and intellectual. We could even describe it as playful. It is quite a departure from the stories he is best known for, but even this story turned out to be enormously influential to generations of writers who came after.