He nodded. We pressed on.
Ten minutes' steady tramping brought us within sight of the Thames. Smith and I both had noticed how Fu-Manchu's activities centered always about the London river. Undoubtedly it was his highway, his line of communication, along which he moved his mysterious forces. The opium den off Shadwell Highway, the mansion upstream, at that hour a smoldering shell; now the hulk lying off the marshes. Always he made his headquarters upon the river. It was significant; and even if to-night's expedition should fail, this was a clew for our future guidance.
"Bear to the right," directed Smith. "We must reconnoiter before making our attack."
We took a path that led directly to the river bank. Before us lay the gray expanse of water, and out upon it moved the busy shipping of the great mercantile city. But this life of the river seemed widely removed from us. The lonely spot where we stood had no kinship with human activity. Its dreariness illuminated by the brilliant moon, it looked indeed a fit setting for an act in such a drama as that wherein we played our parts. When I had lain in the East End opium den, when upon such another night as this I had looked out upon a peaceful Norfolk countryside, the same knowledge of aloofness, of utter detachment from the world of living men, had come to me.
Silently Smith stared out at the distant moving lights.
"Karamaneh merely means a slave," he said irrelevantly.
I made no comment.
"There's the hulk," he added.
The bank upon which we stood dipped in mud slopes to the level of the running tide. Seaward it rose higher, and by a narrow inlet — for we perceived that we were upon a kind of promontory — a rough pier showed. Beneath it was a shadowy shape in the patch of gloom which the moon threw far out upon the softly eddying water. Only one dim light was visible amid this darkness.
"That will be the cabin," said Smith.
Acting upon our prearranged plan, we turned and walked up on to the staging above the hulk. A wooden ladder led out and down to the deck below, and was loosely lashed to a ring on the pier. With every motion of the tidal waters the ladder rose and fell, its rings creaking harshly, against the crazy railing.
"How are we going to get down without being detected?" whispered Smith.
"We've got to risk it," I said grimly.
Without further words my friend climbed around on to the ladder and commenced to descend. I waited until his head disappeared below the level, and, clumsily enough, prepared to follow him.
The hulk at that moment giving an unusually heavy heave, I stumbled, and for one breathless moment looked down upon the glittering surface streaking the darkness beneath me. My foot had slipped, and but that I had a firm grip upon the top rung, that instant, most probably, had marked the end of my share in the fight with Fu-Manchu. As it was I had a narrow escape. I felt something slip from my hip pocket, but the weird creaking of the ladder, the groans of the laboring hulk, and the lapping of the waves about the staging drowned the sound of the splash as my revolver dropped into the river.
Rather white-faced, I think, I joined Smith on the deck. He had witnessed my accident, but —
"We must risk it," he whispered in my ear. "We dare not turn back now."
He plunged into the semi-darkness, making for the cabin, I perforce following.
At the bottom of the ladder we came fully into the light streaming out from the singular apartments at the entrance to which we found ourselves. It was fitted up as a laboratory. A glimpse I had of shelves loaded with jars and bottles, of a table strewn with scientific paraphernalia, with retorts, with tubes of extraordinary shapes, holding living organisms, and with instruments — some of them of a form unknown to my experience. I saw too that books, papers and rolls of parchment littered the bare wooden floor. Then Smith's voice rose above the confused sounds about me, incisive, commanding:
"I have you covered, Dr. Fu-Manchu!"
For Fu-Manchu sat at the table.
The picture that he presented at that moment is one which persistently clings in my memory. In his long, yellow robe, his masklike, intellectual face bent forward amongst the riot of singular objects upon the table, his great, high brow gleaming in the light of the shaded lamp above him, and with the abnormal eyes, filmed and green, raised to us, he seemed a figure from the realms of delirium. But, most amazing circumstance of all, he and his surroundings tallied, almost identically, with the dream-picture which had come to me as I lay chained in the cell!
Some of the large jars about the place held anatomy specimens. A faint smell of opium hung in the air, and playing with the tassel of one of the cushions upon which, as upon a divan, Fu-Manchu was seated, leaped and chattered a little marmoset.
That was an electric moment. I was prepared for anything — for anything except for what really happened.
The doctor's wonderful, evil face betrayed no hint of emotion. The lids flickered over the filmed eyes, and their greenness grew momentarily brighter, and filmed over again.
"Put up your hands!" rapped Smith, "and attempt no tricks." His voice quivered with excitement. "The game's up, Fu-Manchu. Find something to tie him up with, Petrie."
I moved forward to Smith's side, and was about to pass him in the narrow doorway. The hulk moved beneath our feet like a living thing groaning, creaking — and the water lapped about the rotten woodwork with a sound infinitely dreary.
"Put up your hands!" ordered Smith imperatively.
Fu-Manchu slowly raised his hands, and a smile dawned upon the impassive features — a smile that had no mirth in it, only menace, revealing as it did his even, discolored teeth, but leaving the filmed eyes inanimate, dull, inhuman.
He spoke softly, sibilantly.
"I would advise Dr. Petrie to glance behind him before he moves."
Smith's keen gray eyes never for a moment quitted the speaker. The gleaming barrel moved not a hair's-breadth. But I glanced quickly over my shoulder — and stifled a cry of pure horror.
A wicked, pock-marked face, with wolfish fangs bared, and jaundiced eyes squinting obliquely into mine, was within two inches of me. A lean, brown hand and arm, the great thews standing up like cords, held a crescent-shaped knife a fraction of an inch above my jugular vein. A slight movement must have dispatched me; a sweep of the fearful weapon, I doubt not, would have severed my head from my body.
"Smith!" I whispered hoarsely, "don't look around. For God's sake keep him covered. But a dacoit has his knife at my throat!"
Then, for the first time, Smith's hand trembled. But his glance never wavered from the malignant, emotionless countenance of Dr. Fu-Manchu. He clenched his teeth hard, so that the muscles stood out prominently upon his jaw.
I suppose that silence which followed my awful discovery prevailed but a few seconds. To me those seconds were each a lingering death.
There, below, in that groaning hulk, I knew more of icy terror than any of our meetings with the murder-group had brought to me before; and through my brain throbbed a thought: the girl had betrayed us!
"You supposed that I was alone?" suggested Fu-Manchu. "So I was."
Yet no trace of fear had broken through the impassive yellow mask when we had entered.
"But my faithful servant followed you," he added. "I thank him. The honors, Mr. Smith, are mine, I think?"
Smith made no reply. I divined that he was thinking furiously. Fu-Manchu moved his hand to caress the marmoset, which had leaped playfully upon his shoulder, and crouched there gibing at us in a whistling voice.
"Don't stir!" said Smith savagely. "I warn you!"
Fu-Manchu kept his hand raised.
"May I ask you how you discovered my retreat?" he asked.
"This hulk has been watched since dawn," lied Smith brazenly.
"So?"