It was close on midnight when a man crossed the Place de la Concorde. In spite of the handsome fur coat which garbed his meagre form, there was something essentially weak and paltry about him. A little man with a face like a rat. A man, one would say, who could never play a conspicuous part, or rise to prominence in any sphere. And yet, in leaping to such a conclusion, an onlooker would have been wrong. For this man, negligible and inconspicuous as he seemed, played a prominent part in the destiny of the world. In an Empire where rats ruled, he was the king of the rats. Even now, an Embassy awaited his return. But he had business to do first--business of which the Embassy was not officially cognizant. His face gleamed white and sharp in the moonlight. There was the least hint of a curve in the thin nose. His father had been a Polish Jew, a journeyman tailor. It was business such as his father would have loved that took him abroad to-night. He came to the Seine, crossed it, and entered one of the less reputable quarters of Paris. Here he stopped before a tall, dilapidated house and made his way up to an apartment on the fourth floor. He had barely time to knock before the door was opened by a woman who had evidently been awaiting his arrival. She gave him no greeting, but helped him off with his overcoat and then led the way into the tawdrily furnished sitting-room. The electric light was shaded with dirty pink festoons and it softened, but could not disguise, the girl's face with its mask of crude paint. Could not disguise, either, the broad Mongolian cast of her countenance. There was no doubt of Olga Demiroff's profession, nor of her nationality. "All is well, little one?" "All is well, Boris Ivanovitch." He nodded murmuring: "I do not think I have been followed." But there was anxiety in his tone. He went to the window, drawing the curtains aside slightly, and peering carefully out. He started away violently. "There are two men--on the opposite pavement. It looks to me--" He broke off and began gnawing at his nails--a habit he had when anxious. The Russian girl was shaking her head with a slow, reassuring action. "They were here before you came." "All the same, it looks to me as though they were watching this house." "Possibly," she admitted indifferently. "But then--" "What of it? Even if they _know_--it will not be _you_ they will follow from here." A thin, cruel smile came to his lips. "No," he admitted, "that is true." He mused for a minute or two and then observed: "This damned American--he can look after himself as well as anybody." "I suppose so." He went again to the window. "Tough customers," he muttered, with a chuckle. "Known to the police, I fear. Well, well, I wish Brother Apache good hunting." Olga Demiroff shook her head. "If the American is the kind of man they say he is, it will take more than a couple of cowardly apaches to get the better of him." She paused. "I wonder--" "Well?" "Nothing. Only twice this evening a man has passed along this street--a man with white hair." "What of it?" "This. As he passed those two men, he dropped his glove. One of them picked it up and returned it to him. A thread-bare device." "You mean--that the white-haired man is--their employer?" "Something of the kind." The Russian looked alarmed and uneasy. "You are sure--the parcel is safe?...