I stood long by my own door, irresolute, listening, hoping, fearing, my brain throbbing with the effort to seize some clue to the maze of mysteries in which I was entangled. Was the clue behind those locked doors? Did the man whose groans and prayers had startled me hold the heart of the mystery?

The groans and prayers, if they continued, could be heard no longer through the double doors, and I seated myself by the desk and took account of the events that had brought me to my present position. Where did I stand? What had I accomplished? What had I learned? How was I to reach the end for which I struggled and bring to justice the slayer of my murdered friend? As I passed in review the occurrences that had crowded the few weeks since my arrival, I was compelled to confess that I knew little more of the mysteries that surrounded me than on the night I arrived. I knew that I was tossed between two opposing forces. I knew that a mysterious boy was supposed to be under my protection, and that to gain and keep possession of him my life was sought and defended. I knew that Doddridge Knapp had caused the murder of Henry Wilton, and yet for some unfathomable reason gave me his confidence and employment under the belief that I was Henry Wilton. But I had been able to get no hint of who the boy might be, or where he was concealed, or who was the hidden woman who employed me to protect him, or why he was sought by Doddridge Knapp. Mother Borton's vague hints seemed little better than guess-work. If she knew the name of the boy and the identity of the woman, she had some good reason for concealing them. It flashed over my mind that Mother Borton might herself be the mysterious employer. I had never yet seen a line of her handwriting, and the notes might have come from her. It was she who first had told me that my men were already paid, and a few hours later I had found the note from my employer assuring me that the demands were fully settled. Could it be that she was the woman with whom Doddridge Knapp was battling with a desperate purpose that did not stop at murder? The idea was gone as soon as it came. It was preposterous to suppose that these two could feel so overwhelming an interest in the same child.

How long I sat by the desk waiting, thinking, planning, I know not. One scheme of action after another I had considered and rejected, when a sound broke on my listening ears. I started up in feverish anxiety. It was from the room beyond, and I stole toward the door to learn what it might mean.

Again it came, but, strain as I might, I could not determine its cause. What could be going on in the locked office? If two men were there was it a personal encounter? If one man, was he doing violence upon himself? Was the heart of the mystery to be found behind those doors if I had the courage to throw them open? Burning with impatience, I thrust aside the fears of the evil that might follow hasty action. I had drawn the key and raised it once more to the slot, when I heard a step in the middle room. I had but time to retreat to my desk when a key was fitted in the lock, the door was flung open, and Doddridge Knapp stepped calmly into the room.

“Ah, Wilton,” said the King of the Street affably. “I was wondering if I should find you here.”

There was no trace of surprise or agitation in the face before me. If this was the man whose prayers and groans and sobs had come to me through the locked door, if he had wrestled with his conscience or even had been the accusing conscience of another, his face was a mask that showed no trace of the agony of thoughts that might contort the spirit beneath it.

“I was attending to a little work of my own,” I answered, after greeting. If I felt much like a disconcerted pickpocket I was careful to conceal the circumstance, and spoke with easy indifference. “You have come back before I expected you,” I continued carelessly.

“Yes,” said the King of the Street with equal carelessness. “Some family affairs called me home sooner than I had thought to come.”

I had an inward start. Mrs. Knapp's troubled look, Mrs. Bowser's confusion, and the few words that had passed, returned to me. What was the connection between them?

“Mrs. Knapp is not ill, I trust?” I ventured.

“Oh, no.”

“Nor Miss Knapp?”

“Oh, all are well at the house, but sometimes you know women-folks get nervous.”

Was it possible that Mrs. Knapp had sent for her husband? What other meaning could I put on these words? But before I could pursue my investigations further along this line, the wolf came to the surface, and he waved the subject aside with a growl.

“But this is nothing to you. What you want to know is that I won't need you before Wednesday, if then.”

“Does the campaign reopen?” I asked.

“If you don't mind, Wilton,” said the Wolf with another growl, “I'll keep my plans till I'm ready to use them.”

“Certainly,” I retorted. “But maybe you would feel a little interest to know that Rosenheim and Bashford have gathered in about a thousand shares of Omega in the last four or five days.”

Doddridge Knapp gave me a keen glance.

“There were no sales of above a hundred shares,” he said.

“No—most of them ran from ten to fifty shares.”

“Well,” he continued, looking fixedly at me, “you know something about Rosenheim?”

“If it won't interfere with your plans,” I suggested apologetically.

The Wolf drew back his lips over his fangs, and then turned the snarl into a smile. “Go on,” he said, waving amends for the snub he had administered.

“Well, I don't know much about Rosenheim, but I caught him talking with Decker.”

“Were the stocks transferred to Decker?”

“No; they stand to Rosenheim, trustee.”

“Well, Wilton, they've stolen a march on us, but I reckon we'll give 'em a surprise before they're quite awake.”

“And,” I continued coolly, “Decker's working up a deal in Crown Diamond and toying a little with Confidence—you gave me a week to find out, you may remember.”

“Very good, Wilton,” said the King of the Street with grudging approval. “We'll sell old Decker quite a piece of Crown Diamond before he gets through. And now is there anything more in your pack?”

“It's empty,” I confessed. “Well, you may go then.”

I was puzzled to know why Doddridge Knapp should wish to get me out of the office. Was there some secret locked in his room that he feared I might surprise if I stayed? I looked at him sharply, but there was nothing to be read on that impassive face.

Doddridge Knapp followed me to the door, and stood on the threshold as I walked down the hall. There was no chance for spying or listening at keyholes, if I were so inclined, and it was not until I had reached the bottom stair that I thought I heard the sound of a closing door behind me.

As I stood at the entrance, almost oblivious of the throng that was hurrying up and down Clay Street, Porter joined me.

“Did you see him?” he asked.

“Him? Who?”

“Why, Tom Terrill sneaked down those stairs a little bit ago, and I thought you might have found him up there.”

Could it be possible that this man had been with Doddridge Knapp, and that it was his voice I had heard? This in turn seemed improbable, hardly possible.

“There he is now,” whispered Porter.

I turned my eyes in the direction he indicated, and a shock ran through me; for my eye had met the eye of a serpent. Yes, there again was the cruel, keen face, and the glittering, repulsive eye, filled with malice and hatred, that I had beheld with loathing and dread whenever it had come in my path. With an evil glance Terrill turned and made off in the crowd.

“Follow that man, Wainwright,” said I to the second guard, who was close at hand. “Watch him to-night and report to me to-morrow.”

I wondered what could be the meaning of Terrill's visit to the building. Was it to see Doddridge Knapp and get his orders? Or was it to follow up some new plan to wrest from me the secret I was supposed to hold? But there was no answer to these questions, and I turned toward my room to prepare for the excursion that had been set for the evening.

It was with hope and fear that I took my way to the Pine Street palace. It was my fear that was realized. Mrs. Bowser fell to my lot—indeed, I may say that I was surrounded by her in force, and surrendered unconditionally—while Luella joined Mr. Carter, and Mrs. Carter with Mr. Horton followed.

Corson was waiting for us at the old City Hall. I had arranged with the policeman that he should act as our guide, and had given him Porter and Barkhouse as assistants in case any should be needed.

“A fine night for it, sor,” said Corson in greeting. “There's a little celebration goin' on among the haythens to-night, so you'll see 'em at their best.”

“Oh, how sweet!” gushed Mrs. Bowser. “Is it that dear China New Year that I've heard tell on, and do they take you in to dinner at every place you call, and do they really eat rats? Ugh, the horrid things!” And Mrs. Bowser pulled up short in mid career.

“No, ma'am,” said Corson, “leastways it ain't Chaney New Year for a couple of months yet. As for eatin' rats, there's many a thing gets eaten up in the dens that would be better by bein' turned into a rat.”

Looking across the dark shrubbery of Portsmouth Square and up Washington Street, the eye could catch a line of gay-colored lanterns, swaying in the light wind, and casting a mellow glow on buildings and walks.

“Oh, isn't it sweet! So charming!” cried Mrs. Bowser, as we came into full view of the scene and crossed the invisible line that carries one from modern San Francisco into the ancient oriental city, instinct with foreign life, that goes by the name of Chinatown. Sordid and foul as it appears by daylight, there was a charm and romance to it under the lantern-lights that softened the darkness. Windows and doors were illuminated. Brown, flat-nosed men in loose clothing gathered in groups and discussed their affairs in a strange singsong tongue and high-pitched voices. Here, was the sound of the picking of the Chinese banjo-fiddle; there, we heard a cracked voice singing a melancholy song in the confusion of minor keys that may pass for music among the brown men; there, again, a gong with tin-pan accompaniment assisted to reconcile the Chinese to the long intervals between holidays. Crowds hurried along the streets, loitered at corners, gathered about points of interest, but it seemed as though it was all one man repeated over and over.

“Why, they're all alike!” exclaimed Mrs. Bowser. “How do they ever tell each other apart?”

“Oh, that's aisy enough, ma'am,” replied Corson with a twinkle in his eye. “They tie a knot in their pigtails, and that's the way you know 'em.”

“Laws! you don't say!” said Mrs. Bowser, much impressed. “I never could tell 'em that way.”

“It is a strange resemblance,” said Mr. Carter. “Don't you find it almost impossible to distinguish between them?”

“To tell you the truth, sor, no,” said Corson. “It's a trick of the eye with you, sor. If you was to be here with 'em for a month or two you'd niver think there was two of 'em alike. There's as much difference betwixt one and another as with any two white men. I was loike you at first. I says to meself that they're as like as two pease. But, now, look at those two mugs there in that door. They're no more alike than you and me, as Mr. Wilton here can tell you, sor.”

The difference between the two Chinese failed to impress me, but I was mindful of my reputation as an old resident.

“Oh, yes; a very marked contrast,” I said promptly, just as I would have sworn that they were twins if Corson had suggested it.

“Very remarkable!” said Mr. Carter dubiously.

In and out we wound through the oriental city—the fairy-land that stretched away, gay with lanterns and busy with strange crowds, changing at times as we came nearer to a tawdry reality, cheap, dirty, and heavy with odors. Here was a shop where ivory in delicate carvings, bronze work that showed the patient handicraft and grotesque fancy of the oriental artist, lay side by side with porcelains, fine and coarse, decorated with the barbaric taste in form and color that rules the art of the ancient empire. Beyond, were carved cabinets of ebony and sandal-wood, rich brocades and soft silks and the proprietor sang the praises of his wares and reduced his estimate of their value with each step we took toward the door. Next the rich shop was a low den from whose open door poured fumes of tobacco and opium, and in whose misty depths figures of bloused little men huddled around tables and swayed hither and thither. The click of dominoes, the rattling of sticks and counters, and the excited cries of men, rose from the throng.

“They're the biggest gamblers the Ould Nick iver had to his hand,” said Corson; “there isn't one of 'em down there that wouldn't bet the coat off his back.”

“Dear me, how dreadful!” said Mrs. Bowser. “And do we have to go down into that horrible hole, and how can we ever get out with our lives?”

“We're not going down there, ma'am,” interrupted Corson shortly.

“And where next?” asked Luella.

The question was addressed to the policeman, not to me. Except for a formal greeting when we had met, Luella had spoken no word to me during the evening.

“Here's the biggest joss-house in town,” said Corson. “We might as well see it now as any time.”

“Oh, do let us see those delightfully horrible idols,” cried Mrs. Bowser. “But,” she added, with a sudden access of alarm at some recollection of the reading of her school-days, “do they cut people's hearts out before the wicked things right in the middle of the city?”

The policeman assured her that the appetite of the joss for gore remained unsatisfied, and led the way into the dimly-lighted building that served as a temple.

I lingered a moment by the door to see that all my party passed in.

“There's Wainwright,” whispered Porter, who closed the procession.

“Where?” I asked, a dim remembrance of the mission on which I had sent him in pursuit of the snake-eyed man giving the information a sinister twist.

Porter gave a chirrup, and Wainwright halted at the door.

“He's just passed up the alley here,” said Wainwright in a low voice.

“Who? Terrill?” I asked.

“Yes,” said Wainwright. “I've kept him in sight all the evening.”

“Hasn't he seen you?” asked Porter. “I spied you as soon as you turned the corner.”

“Don't know,” said Wainwright; “but something's up. There he goes now. I mustn't miss him.” And Wainwright darted off.

I looked searchingly in the direction he took, but could see no sign of the snake-eyed enemy.

The presence of Terrill gave me some tremors of anxiety, for I knew that his unscrupulous ferocity would stop at nothing. I feared for the moment that some violence might threaten the party, and that perhaps Luella was in danger. Then I reflected that the presence of Doddridge Knapp's daughter was a protection against an attack from Doddridge Knapp's agents, and I followed the party into the heathen temple without further apprehensions.

The temple was small, and even in the dim, religious light that gave an air of mystery to the ugly figure of the god and the trappings of the place, the whole appeared cheap—a poor representative of the majesty of a religion that claims the devotion of four hundred million human beings.

“That's one of the richest carvings ever brought into this country,” said Corson, pointing to a part of the altar mounting. “Tin thousand dollars wouldn't touch one side of it.”

“You don't say!” cried Mrs. Bowser, while the rest murmured in the effort to admire the work of art. “And is that stuff burning for a disinfectant?”

She pointed to numerous pieces of punk, such as serve the small boy on the Fourth of July, that were consuming slowly before the ugly joss.

“No, ma'am—not but they needs it all right enough,” said Corson, “but that's the haythen way of sayin' your prayers.”

This information was so astonishing that Corson was allowed to finish his explanation without further remarks from Mrs. Bowser.

“I'll show you the theater next,” said he, as he led the way out of the temple with Mrs. Bowser giving her views of the picturesque heathen in questions that Corson found no break in the conversation long enough to answer. As I lingered for a moment in some depression of spirit, waiting for the others to file out, a voice that thrilled me spoke in my ear.

“Our guide is enjoying a great favor.” It was Luella, noticing me for the first time since the expedition had started.

“He has every reason to be delighted,” I returned, brightening at the favor I was enjoying.

“Foreign travel is said to be of great value in education,” said Luella, taking my arm, “but it's certainly stupid at times.”

I suspected that Mr. Carter had not been entirely successful in meeting Miss Knapp's ideas of what an escort should be.

“I didn't suppose you could find anything stupid,” I said.

“I am intensely interested,” she retorted, “but unfortunately the list of subjects has come to an end.”

“You might have begun at the beginning again.”

“He did,” she whispered, “so I thought it time he tried the guide or Aunt Julia.”

“Thank you,” I said.

“Thank him, you mean,” she said gaily. “Now don't be stupid yourself, so please change the subject. Do you know,” she continued without giving me time to speak, “that the only way I can be reconciled to this place and the sights we have seen is to imagine I am in Canton or Peking, thousands of miles from home? Seen there, it is interesting, instructive, natural—a part of their people. As a part of San Francisco it is only vile.”

“Ugh!” said I, as a whiff from an underground den floated up on the night air, and Luella caught her handkerchief to her face to get her breath. “I'm not sure that this rose would smell any sweeter by the name of Canton.”

“I'm afraid your argument is too practical for me to answer,” she laughed. “Yet I'm certain it would be more poetic seven thousand miles away.”

“Come this way,” said Corson, halting with the party at one of the doors. “I'll show you through some of the opium dens, and that will bring us to the stage door of the theater.”

“How close and heavy the air is!” said Luella, as we followed the winding passage in the dim illumination that came from an occasional gas-jet or oil lamp.

“The yellow man is a firm believer in the motto, 'Ventilation is the root of all evil,'” I admitted.

The fumes of tobacco and opium were heavy on the air, and a moment later we came on a cluster of small rooms or dens, fitted with couches and bunks. It needed no description to make the purpose plain. The whole process of intoxication by opium was before me, from the heating of the metal pipe to the final stupor that is the gift and end of the Black Smoke. Here, was a coolie mixing the drug; there, just beyond him, was another, drawing whiffs from the bubbling narcotic through the bamboo handle of his pipe; there, still beyond, was another, lying back unconscious, half-clad, repulsive, a very sorry reality indeed to the gorgeous dreams that are reputed to follow in the train of the seductive pipe.

“Do they really allow them to smoke that dreadful stuff?” asked Mrs. Bowser shrilly. “Why, I should think the governor, or the mayor, or you, Mr. Policeman, would stop the awful thing right off. Now, why don't you?”

“Oh, it's no harm to the haythen,” said Corson. “It's death and destruction to the white man, but it's no more to the yellow man than so much tobacco and whiskey. They'll be all right to-morrow. We niver touches 'em unless they takes the whites into their dens. Then we raids 'em. But there's too much of it goin' on, for all that.”

“This is depressing,” said Luella, with a touch on my arm. “Let's go on.”

“Turn to the right there,” Corson called out, as we led the way while he was explaining to Mr. Carter the method of smoking.

“Let us get where there is some air,” said Luella. “This odor is sickening.”

We hastened on, and, turning to the right, soon came on two passages. One led up a stair, hidden by a turn after half a dozen steps. The other stretched fifty or seventy-five feet before us, and an oil lamp on a bracket at the farther end gave a smoky light to the passage and to a mean little court on which it appeared to open.

“We had better wait for the rest,” said Luella cautiously.

As she spoke, one of the doors toward the farther end of the passage swung back, and a tall heavy figure came out. My heart gave a great bound, and I felt without realizing it at the moment, that Luella clutched my arm fiercely.

In the dim light the figure was the figure of the Wolf, the head was the head of the Wolf, and though no light shone upon it, the face was the face of the Wolf, livid, distorted with anger, fear and brutal passions.

“Doddridge Knapp!” I exclaimed, and gave a step forward.

It flashed on me that one mystery was explained. I had found out why the Doddridge Knapp of plot and counterplot, and the Doddridge Knapp who was the generous and confidential employer, could dwell in the same body. The King of the Street was a slave of the Black Smoke, and, like many another, went mad under the influence of the subtle drug.

As I moved forward, Luella clung to me and gave a low cry. The Wolf figure threw one malignant look at us and was gone.

“Take me home, oh, take me home!” cried Luella in low suppressed tones, trembling and half-falling. I put my arm about her to support her.

“What is it?” I asked.

She leaned upon me for one moment, and the black walls and gloomy passage became a palace filled with flowers. Then her strength and resolution returned, and she shook herself free.

“Come; let us go back to the others,” she said a little unsteadily. “We should not have left them.”

“Certainly,” I replied. “They ought to be here by this time.”

But as we turned, a sudden cry sounded as of an order given. There was a bang of wood and a click of metal, and, as we looked, we saw that unseen hands had closed the way to our return. A barred and iron-bound door was locked in our faces.