The proof of his theory seemed so complete he did not think it necessary to make inquiries at Ostend. Indeed, he believed his task was at last accomplished, and he began to consider an immediate return to London.
CHAPTER XXVIII
THE UNRAVELLING OF THE WEB
When La Touche solved the problem of how Boirac had faked his alibi, his first impression was that his work was done. But, as had happened so often before, second thoughts showed him that this was hardly the case. Though he had established Boirac’s guilt to his own satisfaction, he doubted if he could prove it in court, and, indeed, the whole matter was still far from clear.
He felt that if he could only find the carter who had brought the cask to the rue Cardinet he would reach certainty on at least some of the points which were puzzling him. He therefore decided to concentrate once more on this problem.
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?