The scene of our return to Graywater Park is destined to live in my memory for ever. The storm, of which the violet rainfall had been a prelude, gathered blackly over the hills. Ebon clouds lowered upon us as we came racing to the gates. Then the big car was spinning around the carriage sweep, amid a deathly stillness of Nature indescribably gloomy and ominous. I have said, a stillness of nature; but, as Kennedy leapt out and ran up the steps to the door, from the distant cages wherein Sire Lionel kept his collection of rare beasts proceeded the angry howling of the leopards and such a wild succession of roars from the African lioness that I stared at our eccentric host questioningly.  
"It's the gathering storm," he explained. "These creatures are peculiarly susceptible to atmospheric disturbances."
 
Now the door was thrown open, and, standing in the lighted hall, a picture fair to look upon in her dainty kimono and little red, high-heeled slippers, stood Kâramaneh!
 
I was beside her in a moment; for the lovely face was pale and there was a wildness in her eyes which alarmed me.
 
"He is somewhere near!" she whispered, clinging to me. "Some great danger threatens. Where have you been?—what has happened?"
 
"Smith was attacked on his way back from London," I replied. "But, as you see, he is quite recovered. We are in no danger; and I insist that you go back to bed. We shall tell you all about it in the morning."
 
Rebellion blazed up in her wonderful eyes instantly—and as quickly was gone, leaving them exquisitely bright. Two tears, like twin pearls, hung upon the curved black lashes. It made my blood course faster to watch this lovely Eastern girl conquering the barbaric impulses that sometimes flamed up within, her, because I willed it; indeed this was a miracle that I never tired of witnessing.
 
Mrs. Oram, the white-haired housekeeper, placed her arm in motherly fashion about the girl's slim waist.
 
"She wants to stay in my room until the trouble is all over," she said in her refined, sweet voice.
 
"You are very good, Mrs. Oram," I replied. "Take care of her."
 
One long, reassuring glance I gave Kâramaneh, then turned and followed Smith and Sir Lionel up the winding oak stair. Kennedy came close behind me, carrying one of the acetylene head-lamps of the car. And—
 
"Just listen to the lioness, sir!" he whispered. "It's not the gathering storm that's making her so restless. Jungle beasts grow quiet, as a rule, when there's thunder about."
 
The snarling of the great creature was plainly audible, distant though we were from her cage.
 
"Through your room, Barton!" snapped Nayland Smith, when we gained the top corridor.
 
He was his old, masterful self once more, and his voice was vibrant with that suppressed excitement which I knew well. Into the disorderly sleeping apartment of the baronet we hurried, and Smith made for the recess near the bed which concealed a door in the paneling.
 
"Cautiously here!" cried Smith. "Follow immediately behind me, Kennedy, and throw the beam ahead. Hold the lamp well to the left."
 
In we filed, into that ancient passage which had figured in many a black deed but had never served the ends of a more evil plotter than the awful Chinaman who so recently had rediscovered it.
 
Down we marched, and down, but not to the base of the tower, as I had anticipated. At a point which I judged to be about level with the first floor of the house, Smith—who had been audibly counting the steps—paused, and began to examine the seemingly unbroken masonry of the wall.
 
"We have to remember," he muttered, "that this passage may be blocked up or otherwise impassable, and that Fu-Manchu may know of another entrance. Furthermore, since the plan is lost, I have to rely upon my memory for the exact position of the door."
 
He was feeling about in the crevices between the stone blocks of which the wall was constructed.
 
"Twenty-one steps," he muttered; "I feel certain."
 
Suddenly it seemed that his quest had proved successful.
 
"Ah!" he cried—"the ring!"
 
I saw that he had drawn out a large iron ring from some crevice in which it had been concealed.
 
"Stand back, Kennedy!" he warned.
 
Kennedy moved on to a lower step—as Smith, bringing all his weight to bear upon the ring, turned the huge stone slab upon its hidden pivot, so that it fell back upon the stair with a reverberating boom.
 
We all pressed forward to peer into the black cavity. Kennedy moving the light, a square well was revealed, not more than three feet across. Foot-holes were cut at intervals down the further side.
 
"H'm!" said Smith—"I was hardly prepared for this. The method of descent that occurs to me is to lean back against one side and trust one's weight entirely to the foot-holes on the other. A shaft appeared in the plan, I remember, but I had formed no theory respecting the means provided for descending it. Tilt the lamp forward, Kennedy. Good! I can see the floor of the passage below; only about fifteen feet or so down."
 
He stretched his foot across, placed it in the niche and began to descend.
 
"Kennedy next!" came his muffled voice, "with the lamp. Its light will enable you others to see the way."
 
Down went Kennedy without hesitation, the lamp swung from his right arm.
 
"I will bring up the rear," said Sir Lionel Barton.
 
Whereupon I descended. I had climbed down about half-way when, from below, came a loud cry, a sound of scuffling, and a savage exclamation from Smith. Then——
 
"We're right, Petrie! This passage was recently used by Fu-Manchu!"
 
I gained the bottom of the well, and found myself standing in the entrance to an arched passage. Kennedy was directing the light of the lamp down upon the floor.
 
"You see, the door was guarded............