French could scarcely restrain a chuckle of sheer delight as he listened to this statement. It was even more gratifying news than that the girls with whom Welland was dealing were employed in box offices. For here was actual proof that he really was on the right track. The scheme for betting on the Monte Carlo tables connected the cases. When therefore he was investigating the affairs of Curtice Welland, he was on the way to learning who murdered Thurza Darke and her fellow victims. For the second time in two days he experienced that delightful feeling of enthusiasm which came from progress and success. At the same time he was puzzled by the girl’s manner. Experience told him that a true confession produced symptoms of relief. But Miss Moran had shown no such feeling. Indeed, she seemed more uneasy and apprehensive than ever. Gradually an opinion crystallized in French’s mind. He had not heard the truth. This story was an invention and the girl was terrified lest he should see through it. A small test, however, should settle the matter. “Gambling may or may not be wise, Miss Moran,” he said gravely, “but it is certainly not illegal and you have nothing to fear from the police because of it. There surely must be something else. Has your betting tempted you towards the till of the Panopticon?” For a moment an indignant denial seemed imminent, then a fresh idea appeared to dawn on the girl’s mind and she checked herself. “Maybe there was something of the kind,” she said, averting her face as if from shame. But French was certain she was now feeling relief. So the little test had worked, and out of her own mouth the girl stood convicted. French’s previous inquiries had proved that she was not stealing from the till. But she had seen that her story lacked motive and to bolster it up she had admitted a theft of which she was innocent. The business, then, was even more serious than he had supposed. This girl was willing to risk arrest rather than reveal it. But French saw that for the moment he would get no more out of her, and he set himself to dispel her fears, so that the story she would almost certainly tell to Welland would do as little harm as possible. One other point, however, he did learn. At the moment he did not appreciate its importance, but afterwards he saw that its discovery formed an essential link in the chain by which he eventually unravelled the mystery. While going over with Miss Moran the places at which she had been picked up and set down, he remembered that she had not been seen to speak to Welland, and asked how she knew where to wait for the car. Without hesitation she told him that five different places had been chosen, which were used in rotation. This avoided stopping at the same point each day, which might be noticeable, and the number five insured a different place being used on the same day of each week.