I clearly detected a movement myself immediately behind the half-open door of the sitting-room.  Smith started and stared intently across my shoulder at the doorway; then his gaze shifted and became fixed upon my face.

“He bought his life from me, Smith.”

Never can I forget the change that came over my friend’s tanned features at those words; never can I forget the pang that I suffered to see it.  The fire died out of his eyes and he seemed to grow old and weary in a moment.  None too steadily I went on:—­

“He offered a price that I could not resist, Smith.  Try to forgive me, if you can.  I know that I have done a dastardly thing, but—­perhaps a day may come in your own life when you will understand.  He descended with me to a cellar under the empty house, in which some one was locked.  Had I arrested Fu-Manchu this poor captive must have died there of starvation; for no one would ever have suspected that the place had an occupant....”

The door of the sitting-room was thrown open, and, wearing my great-coat over the bizarre costume in which I had found her, with her bare ankles and little red slippers peeping grotesquely from below, and her wonderful cloud of hair rippling over the turned-up collar, Karamaneh came out!

Her great dark eyes were raised to Nayland Smith’s with such an appeal in them—­an appeal for me—­that emotion took me by the throat and had me speechless.  I could not look at either of them; I turned aside and stared into the lighted sitting-room.

How long I stood so God knows, and I never shall; but suddenly I found my hand seized in a vice-like grip, I looked around ... and Smith, holding my fingers fast in that iron grasp, had his left arm about Karamaneh’s shoulders, and his gray eyes were strangely soft, whilst hers were hidden behind her upraised hands.

“Good old Petrie!” said Smith hoarsely.  “Wake up, man; we have to get her to a hotel before they all close, remember. I understand, old man.  That day came in my life long years ago!”

CHAPTER XXXIV

GRAYWATER PARK

“This is a singular situation in which we find ourselves,” I said, “and one that I’m bound to admit I don’t appreciate.”

Nayland Smith stretched his long legs, and lay back in his chair.

“The sudden illness of Sir Lionel is certainly very disturbing,” he replied, “and had there been any possibility of returning to London to-night, I should certainly have availed myself of it, Petrie.  I share your misgivings.  We are intruders at a time like this.”

He stared at me keenly, blowing a wreath of smoke from his lips, and then directing his attention to the cone of ash which crowned his cigar.  I glanced, and not for the first time, toward the quaint old doorway which gave access to a certain corridor.  Then—­

“Apart from the feeling that we intrude,” I continued slowly, “there is a certain sense of unrest.”