The affair soon became a topic of general discussion, and the name of Arsène Lupin excited the public imagination to such an extent that the newspapers filled their columns with the most fantastic stories of his exploits which found ready credence amongst their readers.

But the letter of Arsène Lupin that was published in the Echo de France (no one ever knew how the newspaper obtained it), that letter in which Baron Cahorn was impudently warned of the coming theft, caused considerable excitement. The most fabulous theories were advanced. Some recalled the existence of the famous subterranean tunnels, and that was the line of research pursued by the officers of the law, who searched the house from top to bottom, questioned every stone, studied the wainscoting and the chimneys, the window-frames and the girders in the ceilings. By the light of torches, they examined the immense cellars where the lords of Malaquis were wont to store their munitions and provisions. They sounded the rocky foundation to its very centre. But it was all in vain. They discovered no trace of a subterranean tunnel. No secret passage existed.