In these latter days of his Augean labors to purge England of the unclean thing which had fastened upon her, my friend was more lean and nervous-looking than I had ever known him. His long residence in Burma had rendered him spare and had burned his naturally dark skin to a coppery hue; but now his gray eyes had grown feverishly bright and his face so lean as at times to appear positively emaciated. But I knew that he was as fit as ever. "This lady may be able to answer your first question," he said. "She and her brother were for some time in the household of Dr. Fu-Manchu. In fact, Mr. Weymouth, Karamaneh, as her name implies, was a slave." Weymouth glanced at the beautiful, troubled face with scarcely veiled distrust. "You don't look as though you had come from China, miss," he said, with a sort of unwilling admiration. "I do not come from China," replied Karamaneh. "My father was a pure Bedawee. But my history does not matter." (At times there was something imperious in her manner; and to this her musical accent added force.) "When your brave brother, Inspector Weymouth, and Dr. Fu-Manchu, were swallowed up by the river, Fu-Manchu held a poisoned needle in his hand. The laughter meant that the needle had done its work. Your brother had become mad!" Weymouth turned aside to hide his emotion. "What was on the needle?" he asked huskily. "It was something which he prepared from the venom of a kind of swamp adder," she answered. "It produces madness, but not always death." "He would have had a poor chance," said Smith, "even had he been in complete possession of his senses. At the time of the encounter we must have been some considerable distance from shore, and the fog was impenetrable." "But how do you account for the fact that neither of the bodies have been recovered?" "Ryman of the river police tells me that persons lost at that point are not always recovered--or not until a considerable time later." There was a faint sound from the room above. The news of that tragic happening out in the mist upon the Thames had prostrated poor Mrs. Weymouth. "She hasn't been told half the truth," said her brother-in-law. "She doesn't know about--the poisoned needle. What kind of fiend was this Dr. Fu-Manchu?" He burst out into a sudden blaze of furious resentment. "John never told me much, and you have let mighty little leak into the papers. What was he? Who was he?" Half he addressed the words to Smith, half to Karamaneh.