TIME wore on and seemingly brought us no nearer, or very little nearer, to our goal. So carefully had my friend Nayland Smith excluded the matter from the press that, whilst public interest was much engaged with some of the events in the skein of mystery which he had come from Burma to unravel, outside the Secret Service and the special department of Scotland Yard few people recognized that the several murders, robberies and disappearances formed each a link in a chain; fewer still were aware that a baneful presence was in our midst, that a past master of the evil arts lay concealed somewhere in the metropolis; searched for by the keenest wits which the authorities could direct to the task, but eluding all—triumphant, contemptuous.  
One link in that chain Smith himself for long failed to recognize. Yet it was a big and important link.
 
"Petrie," he said to me one morning, "listen to this:
 
"'… In sight of Shanghai—a clear, dark night. On board the deck of a junk passing close to seaward of the Andaman a blue flare started up. A minute later there was a cry of "Man overboard!"
 
"'Mr. Lewin, the chief officer, who was in charge, stopped the engines. A boat was put out. But no one was recovered. There are sharks in these waters. A fairly heavy sea was running.
 
"'Inquiry showed the missing man to be a James Edwards, second class, booked to Shanghai. I think the name was assumed. The man was some sort of Oriental, and we had had him under close observation.…'"
 
"That's the end of their report," exclaimed Smith.
 
He referred to the two C.I.D. men who had joined the Andaman at the moment of her departure from Tilbury.
 
He carefully lighted his pipe.
 
"IS it a victory for China, Petrie?" he said softly.
 
"Until the great war reveals her secret resources—and I pray that the day be not in my time—we shall never know," I replied.
 
Smith began striding up and down the room.
 
"Whose name," he jerked abruptly, "stands now at the head of our danger list?"
 
He referred to a list which we had compiled of the notable men intervening between the evil genius who secretly had invaded London and the triumph of his cause—the triumph of the yellow races.
 
I glanced at our notes. "Lord Southery," I replied.
 
Smith tossed the morning paper across to me.
 
"Look," he said shortly. "He's dead."
 
I read the account of the peer's death, and glanced at the long obituary notice; but no more than glanced at it. He had but recently returned from the East, and now, after a short illness, had died from some affection of the heart. There had been no intimation that his illness was of a serious nature, and even Smith, who watched over his flock—the flock threatened by the wolf, Fu-Manchu—with jealous zeal, had not suspected that the end was so near.
 
"Do you think he died a natural death, Smith?" I asked.
 
My friend reached across the table and rested the tip of a long finger upon one of the sub-headings to the account:
 
"SIR FRANK NARCOMBE SUMMONED TOO LATE."
 
"You see," said Smith, "Southery died during the night, but Sir Frank Narcombe, arriving a few minutes later, unhesitatingly pronounced death to be due to syncope, and seems to have noticed nothing suspicious."
 
I looked at him thoughtfully.
 
"Sir Frank is a great physician," I said slowly; "but we must remember he would be looking for nothing suspicious."
 
"We must remember," rapped Smith, "that, if Dr. Fu-Manchu is responsible for Southery's death, except to the eye of an expert there would be nothing suspicious to see. Fu-Manchu leaves no clews."
 
"Are you going around?" I asked.
 
Smith shrugged his shoulders.
 
"I think not," he replied. "Either a greater One than Fu-Manchu has taken Lord Southery, or the yellow doctor has done his work so well that no trace remains of his presence in the matter."
 
Leaving his breakfast untasted, he wandered aimlessly about the room, littering the hearth with matches as he constantly relighted his pipe, which went out every few minutes.
 
"It's no good, Petrie," he burst out suddenly; "it cannot be a coincidence. We must go around and see him."
 
An hour later we stood in the silent room, with its drawn blinds and its deathful atmosphere, looking down at the pale, intellectual face of Henry Stradwick, Lord Southery, the greatest engineer of his day. The mind that lay behind that splendid brow had planned the construction of the railway for which Russia had paid so great a price, had conceived the scheme for the canal which, in the near future, was to bring two great continents, a full week's journey nearer one to the other. But now it would plan no more.
 
"He had latterly developed symptoms of angina pectoris," explained the family physician; "but I had not anticipated a fatal termination so soon. I was called about two o'clock this morning, and found Lord Southery in a dangerously exhausted condition. I did all that was possible, and Sir Frank Narcombe was sent for. But shortly before his arrival the patient expired."
 
"I understand, Doctor, that you had been treating Lord Southery for angina pectoris?" I said.
 
"Yes," was the reply, "for some months."
 
"You regard the circumstances of his end as entirely consistent with a death from that cause?"
 
"Certainly. Do you observe anything unusual yourself? Sir Frank Narcombe quite agrees with me. There is surely no room for doubt?"
 
"No," said Smith, tugging reflectively at the lobe of his left ear. "We do not question the accuracy of your diagnosis in any way, sir."
 
The physician seemed puzzled.
 
"But am I not right in supposing that you are connected with the police?" asked the physician.
 
"Neither Dr. Petrie nor myself are in any way connected with the police," answered Smith. "But, nevertheless, I look to you to regard our recent questions as confidential."
 
As we were leaving the house, hushed awesomely in deference to the unseen visitor who had touched Lord Southery with gray, cold fingers, Smith paused, detaining a black-coated man who passed us on the stairs.
 
"You were Lord Southery's valet?"
 
The man bowed.
 
"Were you in the room at the moment of his fatal seizure?"
 
"I was, sir."
 
"Did you see or hear anything unusual—anything unaccountable?"
 
"Nothing, sir."
 
"No strange sounds outside the house, for instance?"
 
The man shook his head, and Smith, taking my arm, passed out into the street.
 
"Perhaps this business is making me imaginative," he said; "but there seems to be something tainting the air in yonder—something peculiar to houses whose doors bear the invisible death-mark of Fu-Manchu."
 
"You are right, Smith!" I cried. "I hesitated to mention the matter, but I, too, have developed some other sense which warns me of the Doctor's presence. Although there is not a scrap of confirmatory evidence, I am as sure that he has brought about Lord Southery's death as if I had seen him strike the blow."
 
It was in that torturing frame of mind—chained, helpless, in our ignorance, or by reason of the Chinaman's supernormal genius—that we lived throughout the ensuing days. My friend began to look like a man consumed by a burning fever. Yet, we could not act.
 
In the growing dark of an evening shortly following I stood idly turning over some of the works exposed for sale outside a second-hand bookseller's in New Oxford Street. One dealing with the secret societies of China struck me as being likely to prove instructive, and I was about to call the shopman when I was startled to feel a hand clutch my arm.
 
I turned around rapidly—and was looking into the darkly beautiful eyes of Karamaneh! She—whom I had seen in so many guises—was dressed in a perfectly fitting walking habit, and had much of her wonderful hair concealed beneath a fashionable hat.
 
She glanced about her apprehensively.
 
"Quick! Come round the corner. I must speak to you," she said, her musical voice thrilling with excitement.
 
I never was quite master of myself in her presence. He must have been a man of ice who could have been, I think, for her beauty had all the bouquet of rarity; she was a mystery—and mystery adds charm to a woman. Probably she should have been under arrest, but I know I would have risked much to save her from it.
 
As we turned into a quiet thoroughfare she stopped and said:
 
"I am in distress. You have often asked me to enable you to capture Dr. Fu-Manchu. I am prepared to do so."
 
I could scarcely believe that I heard right.
 
"Your brother—" I began.
 
She seized my arm entreatingly, looking into my eyes.
 
"You are a doctor," she said. "I want you to come and see him now."
 
"What! Is he in London?"
 
"He is at the house of Dr. Fu-Manchu."
 
"And you would have me—"
 
"Accompany............