He returned to his office. The young Italian girl still stood by his desk holding the basket of flowers. He gave her more than the amount she asked for, and, bowing low and smiling, she left the office: Referring to his call index, he found that T 697 was that of a young man, Tarleton, belonging to a wealthy family, who was the buyer for a manufactory of electrical machines. In their construction, a large quantity of platinum was used, a metal more valuable, weight for weight, than gold. His purchases had been very heavy, but a checking up of stock used showed that not half of it had been applied to actual construction. The question was--“What had become of the missing metal?” and that question it was No. 42's business to answer. Mr. Isburn was a frequenter of clubs and social functions, partly because he enjoyed them, but, principally, because many valuable clues had been run across while attending them. He had been invited to be a guest at a reception tendered to an Indian Maharajah. He knew that the East Indian princes were profuse in their use of gems and he decided to wear the ruby, for it was a beautiful stone and would be sure to attract the Maharajah's attention. On opening the brass apple he found, to his astonishment, that the ring was gone. Three days later Miss Dana returned and made her report on the Tarleton case. The young man had stolen the platinum, sold it, and lost the money in speculation. His rich father had made good the company's loss, and there would be no prosecution. “He'll be a bigger criminal some day,” remarked Mr. Isburn. “Money saved him,” said Miss Dana. “While I was in the town a workman stole a pound of brass screws--he is a poor inventor and needed them to complete a model, and he got six months in jail.” “Miss Dana, what punishment would be adequate for the thief who stole my ruby?” She laughed, and said: “Anybody smart enough to do it, should have a reward.” “The reward,” said he, “will go to the one who finds and returns it.” “You are joking, Mr. Isburn.” “I wish I were. No, it is gone. I cannot imagine how it was possible for any one to get possession of that ring. Only you and I knew how to open the bookcase doors, and I would as soon suspect myself as you.” “I am glad that you have that opinion,” said Miss Dana. “I have thought several times that I was sorry that you told me about it, for I have felt that if anything happened I should be an object of suspicion.” “Oh, no,” cried Mr. Isburn. “No such suspicion ever entered my mind. I could not be so mean and ungenerous as to think such a thing. The only person I suspect is an Italian girl who came in here to sell some flowers. It was the day I received the long distance telephone message from you in regard to the Tarleton case. I was only out of the room a few minutes, and when I came back she was standing just where I left her.” “It would be like looking for a needle in a haystack to find that girl,” said Miss Dana.