What an insistent piece of green paper that marked bill was! It had started him on this remarkable series of adventures. It had introduced excitable little Poritol and the suave Alcatrante to his apartment. It had made him the victim of the attack by the two Japanese. It had brought the girl into his life. And now it came again into his possession just at the moment to prove that he was on the right track in his search for Maku and the man who had the papers. The queerest coincidence was that the bill would never have come into his possession at all, had it not been for his first meeting with the girl--who at that very time was herself searching for it. The rubbing of his hat against the wheel of her car--on so little thing as that had hinged the events that followed. "This is strange," Orme addressed the woman. "It doesn't hurt it any," said the woman, indifferently. "I know that. But it's a curious thing just the same." The woman raised her shoulders slightly, and began to put away the stock she had taken out for Orme's benefit. "Who paid this to you?" persisted Orme. "How should I remember? I can't keep track of all the persons that come in the store during the day." "But I should think that anything so queer as this----" He saw that he could get nothing from her except by annoying her. The woman glared. "What you a botherin' about? Why don't you leave well enough alone?" Orme smiled. "Tell me one thing," he said, "do you know a Japanese that lives hereabouts?" "Oh," said the woman, "so you're one of the gentlemen he was expectin', eh? Well, it's the front flat, two flights up." "Thank you," said Orme. He walked out to the street, whence a backward glance showed him the woman again concealed in her newspaper. At one side of the shop he found the entrance to a flight of stairs which led to the floors above. In the little hallway, just before the narrow ascent began, was a row of electric buttons and names, and under each of them a mail-box. "3a" had a card on which was printed: "Arima, Teacher of Original Kano Jiu-Jitsu." Should he go boldly up and present himself as a prospective pupil? If Arima were the one who had so effectively thrown him the night before, he would certainly remember the man he had thrown and would promptly be on his guard. Also, the woman in the shop had said, "you are _one_ of the gentlemen he was expectin'." Others were coming.