“You have nothing to fear,” I whispered; “see, he is reviving.  In a few moments all will be well with him.”

The hanging lamp with its garishly colored shade swung gently above us, wafted, it seemed, by some draught which passed through the apartment.  The boy’s heavy lids began to quiver, and Karamaneh nervously clutched my arm, and held me so whilst we watched for the long-lashed eyes to open.  The stillness of the place was positively unnatural; it seemed inconceivable that all about us was the discordant activity of the commercial East End.  Indeed, this eerie silence was becoming oppressive; it began positively to appall me.

Inspector Weymouth’s wondering face peeped over my shoulder.

“Where is Dr. Fu-Manchu?” I whispered, as Nayland Smith in turn appeared beside me.  “I cannot understand the silence of the house—­”

“Look about,” replied Karamaneh, never taking her eyes from the face of Aziz.

I peered around the shadowy walls.  Tall glass cases there were, shelves and niches:  where once, from the gallery above, I had seen the tubes and retorts, the jars of unfamiliar organisms, the books of unfamiliar lore, the impedimenta of the occult student and man of science—­the visible evidences of Fu-Manchu’s presence.  Shelves—­cases—­niches—­were bare.  Of the complicated appliances unknown to civilized laboratories, wherewith he pursued his strange experiments, of the tubes wherein he isolated the bacilli of unclassified diseases, of the yellow-bound volumes for a glimpse at which (had they known of their contents) the great men of Harley Street would have given a fortune—­no trace remained.  The silken cushions; the inlaid tables; all were gone.

The room was stripped, dismantled.  Had Fu-Manchu fled?  The silence assumed a new significance.  His dacoits and kindred ministers of death all must have fled, too.

“You have let him escape us!” I said rapidly.  “You promised to aid us to capture him—­to send us a message—­ and you have delayed until—­”

“No,” she said; “no!” and clutched at my arm again.  “Oh! is he not reviving slowly?  Are you sure you have made no mistake?”

Her thoughts were all for the boy; and her solicitude touched me.  I again examined Aziz, the most remarkable patient of my busy professional career.

As I counted the strengthening pulse, he opened his dark eyes—­ which were so like the eyes of Karamaneh—­and, with the girl’s eager arms tightly about him, sat up, looking wonderingly around.

Karamaneh pressed her cheek to his, whispering loving words in that softly spoken Arabic which had first betrayed her nationality to Nayland Smith.  I handed her my flask, which I had filled with wine.

“My promise is fulfilled!” I said.  “You are free!  Now for Fu-Manchu!  But first let us admit the police to this house; there is something uncanny in its stillness.”

“No,” she replied.  “First let my brother be taken out and placed in safety.  Will you carry him?”