He rested one bony hand on his hip, narrowing the long eyes as he looked down on us.  The purposeful cruelty of the man was inherent; it was entirely untheatrical.  Still Smith remained silent.

“So I am determined to remove you from the scene of your blunders!” added Fu-Manchu.

“Opium will very shortly do the same for you!” I rapped at him savagely.

Without emotion he turned the narrowed eyes upon me.

“That is a matter of opinion, Doctor,” he said.  “You may have lacked the opportunities which have been mine for studying that subject—­ and in any event I shall not be privileged to enjoy your advice in the future.”

“You will not long outlive me,” I replied.  “And our deaths will not profit you, incidentally; because—­” Smith’s foot touched mine.

“Because?” inquired Fu-Manchu softly.

“Ah!  Mr. Smith is so prudent!  He is thinking that I have files!” He pronounced the word in a way that made me shudder.  “Mr. Smith has seen a wire jacket!  Have you ever seen a wire jacket?  As a surgeon its functions would interest you!”

I stifled a cry that rose to my lips; for, with a shrill whistling sound, a small shape came bounding into the dimly lit vault, then shot upward.  A marmoset landed on the shoulder of Dr. Fu-Manchu and peered grotesquely into the dreadful yellow face.  The Doctor raised his bony hand and fondled the little creature, crooning to it.

“One of my pets, Mr. Smith,” he said, suddenly opening his eyes fully so that they blazed like green lamps.  “I have others, equally useful.  My scorpions—­have you met my scorpions?  No?  My pythons and hamadryads?  Then there are my fungi and my tiny allies, the bacilli.  I have a collection in my laboratory quite unique.  Have you ever visited Molokai, the leper island, Doctor?  No?  But Mr. Nayland Smith will be familiar with the asylum at Rangoon!  And we must not forget my black spiders, with their diamond eyes—­ my spiders, that sit in the dark and watch—­then leap!”

He raised his lean hands, so that the sleeve of the robe fell back to the elbow, and the ape dropped, chattering, to the floor and ran from the cellar.

“O God of Cathay!” he cried, “by what death shall these die—­ these miserable ones who would bind thine Empire, which is boundless!”

Like some priest of Tezcat he stood, his eyes upraised to the roof, his lean body quivering—­a sight to shock the most unimpressionable mind.

“He is mad!” I whispered to Smith.  “God help us, the man is a dangerous homicidal maniac!”

Nayland Smith’s tanned face was very drawn, but he shook his head grimly.

“Dangerous, yes, I agree,” he muttered; “his existence is a danger to the entire white race which, now, we are powerless to avert.”

Dr. Fu-Manchu recovered himself, took up the lantern and, turning abruptly, walked to the door, with his awkward, yet feline gait.  At the threshold be looked back.