One evening, in the month of June, 1807, a policeman on his rounds noticed in one of the squares in the town of Cassel a young man behaving very strangely, and speechifying in the middle of a crowd. He drew near, and ascertained that the individual, who was very excited, was pouring forth a stream of insults and threats against Napoleon, whom he went so far as to call “a good-for-nothing scamp.” This was quite enough to decide the representative of public order upon arresting the silly fellow. He was taken off to the police station and questioned. He stated that his name was Jean-Rodolphe Bourcard, “formerly a ribbon manufacturer,” aged twenty-three years, and that he was a native of Basle, in Switzerland. In the course of his examination it was discovered that he had arrived the same day from Hamburg, and that he was full of some very suspicious projects. His story caused him to be suspected, and a report was promptly drawn up for transmission to Paris. Cassel was destined before very long to become the capital of the new kingdom of Westphalia, created for Jerome Bonaparte, and the police supervision of _émigrés_ was exercised as strictly there as in every other part of France. While waiting for orders a search was made in the lodging-house whence the prisoner had come. Nothing much was found in his scanty luggage; some papers, one of which was “a plan and a description of the battle of Austerlitz,” and besides this two or three apparently mysterious notes. One of them contained the words: “_Must see Louis--without Louis nothing can be done_.” Everything was minutely collected together, and some days later Bourcard was sent off for a compulsory visit to Paris. He was put in the Temple, and, although it was easy to see from his talk and his strange behaviour that he was a madman, subject to fits of violence, Fouché could not make up his mind to let him go. The examination of his record and the papers which were found in his possession had suddenly given the Minister an ingenious idea. Who could this _Louis_ be who was obviously connected with Bourcard? Certainly a Royalist spy, since the man of Basle had just come from Hamburg, the headquarters of these people. And the Record Office of the Ministry contained many notes referring to a “well-known agent of England and of Austria,” Baron Louis d’Auerweck of Steilengels, who was known to be living on the banks of the Rhine. There was no room for doubt: this person “had assumed the name of Louis in the various missions which he had undertaken.” Was not this the man who was denoted by Bourcard’s note?