The telephone bell rang.

“Hullo!” cried Eltham—­“hard luck, Doctor!”—­but I could see that he welcomed the interruption.  “Why!” he added, “it is one o’clock!”

I went to the telephone.

“Is that Dr. Petrie?” inquired a woman’s voice.

“Yes; who is speaking?”

“Mrs. Hewett has been taken more seriously ill.  Could you come at once?”

“Certainly,” I replied, for Mrs. Hewett was not only a profitable patient but an estimable lady—­“I shall be with you in a quarter of an hour.”

I hung up the receiver.

“Something urgent?” asked Eltham, emptying his pipe.

“Sounds like it.  You had better turn in.”

“I should much prefer to walk over with you, if it would not be intruding.  Our conversation has ill prepared me for sleep.”

“Right!” I said; for I welcomed his company; and three minutes later we were striding across the deserted common.

A sort of mist floated amongst the trees, seeming in the moonlight like a veil draped from trunk to trunk, as in silence we passed the Mound pond, and struck out for the north side of the common.

I suppose the presence of Eltham and the irritating recollection of his half-confidence were the responsible factors, but my mind persistently dwelt upon the subject of Fu-Manchu and the atrocities which he had committed during his sojourn in England.  So actively was my imagination at work that I felt again the menace which so long had hung over me; I felt as though that murderous yellow cloud still cast its shadow upon England.  And I found myself longing for the company of Nayland Smith.  I cannot state what was the nature of Eltham’s reflections, but I can guess; for he was as silent as I.

It was with a conscious effort that I shook myself out of this morbidly reflective mood, on finding that we had crossed the common and were come to the abode of my patient.

“I shall take a little walk,” announced Eltham; “for I gather that you don’t expect to be detained long?  I shall never be out of sight of the door, of course.”

“Very well,” I replied, and ran up the steps.

There were no lights to be seen in any of the windows, which circumstance rather surprised me, as my patient occupied, or had occupied when last I had visited her, a first-floor bedroom in the front of the house.  My knocking and ringing produced no response for three or four minutes; then, as I persisted, a scantily clothed and half awake maid servant unbarred the door and stared at me stupidly in the moonlight.

“Mrs. Hewett requires me?” I asked abruptly.

The girl stared more stupidly than ever.

“No, sir,” she said, “she don’t, sir; she’s fast asleep!”

“But some one ’phoned me!” I insisted, rather irritably, I fear.

“Not from here, sir,” declared the now wide-eyed girl.  “We haven’t got a telephone, sir.”