Presently we quitted that house upon which the fateful Chinaman had set his seal, as the suburb was awakening to a new day.  The clank of milk-cans was my final impression of the avenue to which a dreadful minister of death had come at the bidding of the death lord.  We left Inspector Weymouth in charge and returned to my rooms, scarcely exchanging a word upon the way.

Nayland Smith, ignoring my entreaties, composed himself for slumber in the white cane chair in my study.  About noon he retired to the bathroom, and returning, made a pretense of breakfast; then resumed his seat in the cane armchair.  Carter reported in the afternoon, but his report was merely formal.  Returning from my round of professional visits at half past five, I found Nayland Smith in the same position; and so the day waned into evening, and dusk fell uneventfully.

In the corner of the big room by the empty fireplace, Nayland Smith lay, with his long, lean frame extended in the white cane chair.  A tumbler, from which two straws protruded, stood by his right elbow, and a perfect continent of tobacco smoke lay between us, wafted toward the door by the draught from an open window.  He had littered the hearth with matches and tobacco ash, being the most untidy smoker I have ever met; and save for his frequent rapping-out of his pipe bowl and perpetual striking of matches, he had shown no sign of activity for the past hour.  Collarless and wearing an old tweed jacket, he had spent the evening, as he had spent the day, in the cane chair, only quitting it for some ten minutes, or less, to toy with dinner.

My several attempts at conversation had elicited nothing but growls; therefore, as dusk descended, having dismissed my few patients, I busied myself collating my notes upon the renewed activity of the Yellow Doctor, and was thus engaged when the ’phone bell disturbed me.  It was Smith who was wanted, however; and he went out eagerly, leaving me to my task.

At the end of a lengthy conversation, he returned from the ’phone and began, restlessly, to pace the room.  I made a pretense of continuing my labors, but covertly I was watching him.  He was twitching at the lobe of his left ear, and his face was a study in perplexity.  Abruptly he burst out: 

“I shall throw the thing up, Petrie!  Either I am growing too old to cope with such an adversary as Fu-Manchu, or else my intellect has become dull.  I cannot seem to think clearly or consistently.  For the Doctor, this crime, this removal of Slattin, is clumsy—­unfinished.  There are two explanations.  Either he, too, is losing his old cunning or he has been interrupted!”

“Interrupted!”

“Take the facts, Petrie,”—­Smith clapped his hands upon my table and bent down, peering into my eyes—­“is it characteristic of Fu-Manchu to kill a man by the direct agency of a snake and to implicate one of his own damnable servants in this way?”

“But we have found no snake!”