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 Karamaneh, 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.”