The butler looked surprised and interested. ‘It is curious, monsieur, that you should ask me that, for I don’t remember mentioning anything about it. I also thought at first it was Calais. I thought the operator said ‘Calais wants you,’ and I was surprised, for I did not know M. Boirac intended to leave Paris. But I was wrong, for when M. Boirac began to speak I asked him the direct question. ‘You are speaking from Calais?’ I said. ‘No,’ he answered, ‘from Charenton.’ I am sure now it was my mistake and that what I thought was Calais was really Charenton. I am not very quick and on the telephone these names sound very much alike. Strange your making the same mistake.’ ‘It is curious,’ admitted La Touche, ‘almost like one of those extraordinary cases of thought transference you read of. However, I am obliged for your confirmation that it was Charenton,’ and he diverted the conversation into other channels. His next visit was to the Telephone Central. Here at first they were not keen to give him any information, but on producing his card and confidentially explaining his business to the head of the department, he obtained what he wanted. Inquiries were made from Calais by wire, and after a considerable delay he was informed that at 2.32 and 2.44 on the Tuesday in question calls were made on Paris. The demand came from the public call office and were for the following numbers: Passy 386 and Nord 745. When La Touche found from the directory that these numbers were those of M. Boirac’s house and office respectively, he could hardly refrain from laughing aloud. ‘How, I wonder,’ he thought, ‘did Lefarge neglect so obvious a check on the Charenton messages?’ Then it occurred to him that probably only inter-urban calls were so noted. 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.