He glanced toward the Burman, who retired immediately, to re-enter a moment later carrying a curious leather sack, in shape not unlike that of a sakka or Arab water-carrier. Opening a little trap in the top of the first compartment of the cage (that is, the compartment which covered Smith’s bare feet and ankles) he inserted the neck of the sack, then suddenly seized it by the bottom and shook it vigorously. Before my horrified gaze four huge rats came tumbling out from the bag into the cage! The dacoit snatched away the sack and snapped the shutter fast. A moving mist obscured my sight, a mist through which I saw the green eyes of Dr. Fu-Manchu fixed upon me, and through which, as from a great distance, his voice, sunk to a snake-like hiss, came to my ears.  
“Cantonese rats, Dr. Petrie, the most ravenous in the world... they have eaten nothing for nearly a week!”
 
Then all became blurred as though a painter with a brush steeped in red had smudged out the details of the picture. For an indefinite period, which seemed like many minutes yet probably was only a few seconds, I saw nothing and heard nothing; my sensory nerves were dulled entirely. From this state I was awakened and brought back to the realities by a sound which ever afterward I was doomed to associate with that ghastly scene.
 
This was the squealing of the rats.
 
The red mist seemed to disperse at that, and with frightfully intense interest, I began to study the awful torture to which Nayland Smith was being subjected. The dacoit had disappeared, and Fu-Manchu placidly was watching the four lean and hideous animals in the cage. As I also turned my eyes in that direction, the rats overcame their temporary fear, and began...
 
“You have been good enough to notice,” said the Chinaman, his voice still sunk in that sibilant whisper, “my partiality for dumb allies. You have met my scorpions, my death-adders, my baboon-man. The uses of such a playful little animal as a marmoset have never been fully appreciated before, I think, but to an indiscretion of this last-named pet of mine, I seem to remember that you owed something in the past, Dr. Petrie...”
 
Nayland Smith stifled a deep groan. One rapid glance I ventured at his face. It was a grayish hue, now, and dank with perspiration. His gaze met mine.
 
The rats had almost ceased squealing.
 
“Much depends upon yourself, Doctor,” continued Fu-Manchu, slightly raising his voice. “I credit Mr. Commissioner Nayland Smith with courage high enough to sustain the raising of all the gates; but I estimate the strength of your friendship highly, also, and predict that you will use the sword of the samurai certainly not later than the time when I shall raise the third gate....”
 
A low shuddering sound, which I cannot hope to describe, but alas I can never forget, broke from the lips of the tortured man.
 
“In China,” resumed Fu-Manchu, “we call this quaint fancy the Six Gates of joyful Wisdom. The first gate, by which the rats are admitted, is called the Gate of joyous Hope; the second, the Gate of Mirthful Doubt. The third gate is poetically named, the Gate of True Rapture, and the fourth, the Gate of Gentle Sorrow. I once was honored in the friendship of an exalted mandarin who sustained the course of joyful Wisdom to the raising of the Fifth Gate (called the Gate of Sweet Desires) and the admission of the twentieth rat. I esteem him almost equally with my ancestors. The Sixth, or Gate Celestial—whereby a man enters into the joy of Complete Understanding—I have dispensed with, here, substituting a Japanese fancy of an antiquity nearly as great and honorable. The introduction of this element of speculation, I count a happy thought, and accordingly take pride to myself.”
 
“The sword, Petrie!” whispered Smith. I should not have recognized his voice, but he spoke quite evenly and steadily. “I rely upon you, old man, to spare me the humiliation of asking mercy from that yellow fiend!”
 
My mind throughout this time had been gaining a sort of dreadful clarity. I had avoided looking at the sword of hara-kiri, but my thoughts had been leading me mercilessly up to the point at which we were now arrived. No vestige of anger, of co............