Since the sending out of his circular to the managers of the various carting establishments in the city, he had interviewed no less than twenty-seven more or less clean-shaven, white-haired, and sharp-featured carters. But all to no purpose. The man he wanted was not among them. And as answers to practically all his circulars had been received, he had reluctantly come to the conclusion his plan had failed. That evening, when Mallet called to make his customary report on Boirac’s doings, the two men discussed the matter, and it was a remark dropped by his assistant that turned La Touche’s thoughts to a point he had previously overlooked. ‘Why do you think he was employed by a cartage contractor?’ Mallet had asked, and La Touche had been going to reply with some asperity that cartage contractors were not uncommonly found to employ carters, when the pertinence of the other’s question struck him. Why, indeed? Of the thousands of carters in Paris, only a small proportion were employed by cartage firms. By far the greater number worked for specific businesses. Might not the man who brought the cask to the goods station belong to this class, and if so, might not this account for the failure of the original advertisements? If a carter were bribed to use his employer’s vehicle for his own gain he would not afterwards give the fact away. And to La Touche it seemed that such a move would be just what might be expected from a man of Boirac’s mentality. But if this theory were correct; if the carter had thus been bound over to silence, how was the man to be discovered and the truth wrung from him? La Touche smoked two cigars over this problem, and then it occurred to him that the method he had already adopted was sound as far as it went. It merely did not go far enough. The only way in which he could ensure finding his hypothetical carter would be to send a circular to every employer in Paris. But that was too large an order. That night, he discussed the matter with the two porters, whom he found intelligent men and keenly interested in the inquiry. He made them describe the kind of cart the cask was brought in, then with a directory he marked off the trades in which the employment of such a vehicle was likely. When he had finished, though some thousands of names were included, he did not think the number overwhelming. For a considerable time he pondered the question of advertising his circular in the press. At last he decided he could not do so, as if Boirac saw it he would doubtless take precautions to prevent the truth becoming known. La Touche therefore returned to the office of the Business Supplies Company and instructed them to send his circular to each of the thousands of employers in the selected trades, they tabulating the replies and giving him the summary. Though he was by no means sanguine of the success of this move, he felt it offered a chance.