"Why, I will tell you," replied the Prefect, as he gave a long, steady, and contemplative puff, and settle'd himself in his chair. "I will tell you in a few words; but, before I begin, let me caution you that this is an affair demanding the greatest secrecy, and that I should most probably lose the position I now hold were it known that I confided it to any one." "Proceed," said I. "Or not," said Dupin. "Well, then; I have received personal information, from a very high quarter, that a certain document of the last importance has been purloined from the royal apartments. The individual who purloined it is known; this beyond a doubt; he was seen to take it. It is known, also, that it still remains in his possession." "How is this known?" asked Dupin. "It is clearly inferred," replied the Prefect, "from the nature of the document, and from the non-appearance of certain results which would at once arise from its passing _out_ of the robber's possession; that is to say, from his employing it as he must design in the end to employ it." "Be a little more explicit," I said. "Well, I may venture so far as to say that the paper gives its holder a certain power in a certain quarter where such power is immensely valuable." The Prefect was fond of the cant of diplomacy. "Still I do not quite understand," said Dupin. "No? well; the disclosure of the document to a third person, who shall be nameless, would bring in question the honor of a personage of most exalted station; and this fact gives the holder of the document an ascendency over the illustrious personage whose honor and peace are so jeopardized." "But this ascendency," I interposed, "would depend upon the robber's knowledge of the loser's knowledge of the robber. Who would dare--"