The Purloined Letter (1845) is one of Poe's detective stories featuring his detective character C. Auguste Dupin, who was introduced in The Murders of the Rue Morgue (1841) and seen again in The Mystery of the Marie Roget (1842).

the case which is causing the problem. The Prefect, brushing this aside, recounts the facts of the case so far.A letter has been purloined (stolen) from the royal apartments. Whilst the identity of the thief is beyond doubt, the letter cannot be found. The letter was received by an unnamed woman (the Queen), who was reading it in her chambers when she was interrupted by an another unnamed “exalted personage” (the King). The letter, it can be inferred, was from some lover, as the Queen is anxious to conceal it from her husband. However, unable to hide it quickly without drawing attention to it she leaves it folded on a table.When a third person, a Minister, enters the room, he notes the Queen’s distress and also spies the letter on the table, its address evident. He devises an elaborate ruse to exchange the letter – leaving one of his own on the table near it, then picking up the offending letter as he is ready to depart. The Queen sees this, but is unable to stop him without drawing the King’s attention to the letter, which she dares not do. The Minister has used the letter to blackmail the Queen, and she has turned to the police to help her retrieve the letter without her husband’s knowledge. The Prefect, convinced the letter must still be in the minister’s possession, as it is on its ownership he bases his power plays, has mounted a comprehensive secret search of the minister’s apartments. In the cover of night he has searched every inch of the residence – looking for secret compartment in desks, hollow cavities in walls or furniture, under floorboards and carpets, even inside books. He has even arranged for the Minister to be waylaid by apparent muggers and searched thoroughly. The letter, it seems, has vanished, yet the prefect is sure this can not be so. He is also sure that the Minister, given the instability of his affairs in the court, would keep the letter readily on hand so that he can use it at a moment’s notice to gain advantage.The Prefect having shared his tale is disappointed by the only advice Dupin offers – to make a thorough re-research of the premises – and leaves. He visits the pair again a month later and, when questioned by the narrator, reports that the new search has been unsuccessful. Dupin asks him about the reward being offered by the Queen for the letter’s return. The Prefect says he can not say, but avers he would give a personal cheque for anyone who could give him the letter. Dupin has him write such a cheque and then produces the letter from his safe. The Prefect leaves, clutching the letter joyously.After his departure, Dupin tells the narrator how he managed to procure the letter. He has visited the minister in his apartment wearing green glasses which conceal his eyes. He has then sat apparently socializing with the minister, at the same time studying his surrounds with his concealed eyes. He has seen what he believes to be the letter, disguised in a pile of correspondence by altering its appearance. He has returned the next day on the pretence of collecting a snuff box he has left behind. While he is there a disturbance in the street (prearranged by Dupin) distracts the minister, giving Dupin time to exchange the letter with a note of his own. Dupin tells the narrator that the problem with the police investigation was, as he told the Prefect on his first visit, in overlooking its simplicity. The minister has predicted the detailed search and, rather than taking elaborate steps to conceal it, has taken them to leave it lying in the open.