Poe’s “The Purloined Letter” was written as two conversations to further strengthen the dual nature of the piece. The concept of duality is the central focus of the story. The thread that carries the dual nature of the story is actually never directly stated, which is that Dupin and Minister D are brothers. Evidence of this first comes from Dupin explaining why the Police failed. He used the example of the “game of 'even and odd'”, where in order to win, the player has to think like the opponent, and thus know the opponent’s mind well. Like the game, Dupin’s sureness that he has indeed solved the crime hinged on how well he knew Minister D. Since he was right, Poe established Dupin as Minister D’s dual nature, his opposite. Another example
