In the short detective story The Purloined Letter, police know who stole a letter that contained valuable information, but are unable to find the letter itself. Some time later, the detective C. Auguste Dupin is able to hand over the letter to the police, having used logic and deductive reasoning to find it. While the police looked in real hiding places for the letter, Dupin decided to look in plain sight, often the best hiding place of all. The story is one of the earliest in the detective story genre.
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