After all, it was essential that Werner be kept in ignorance of my suspicions, granting they were correct.  It would be fatal if I should frighten him inadvertently, so that he would take to flight.  Realizing my foolhardiness, I returned to my chair at last, picking up a magazine at random.  I did so not a moment too soon.  A slight sound caught my ear and I looked up to see the valet already halfway into the room.  His tread was so soft I never would have heard him.

“I don’t think I’ll wait any longer,” I remarked, rising and stretching slightly, as though I had been seated all the time.  “I’ll ring up a little later; perhaps come back after I get in touch with Mr. Werner.”

“Who shall I say was here, sah?” the boy asked, with just a trace of darky dialect.

Above all I didn’t want to alarm Werner.  I could not repeat the explanation I had allowed the attendant downstairs to assume from my remark, that I was a friend who had been out with the director the night before.  I should have to take a chance that Werner’s servant and the hallboy would not compare notes, and that the latter would say nothing to the director upon his arrival.

“I’m an old friend from the Coast,” I explained, with a show of taking the negro into my confidence.  “I wanted to surprise him and so”—­I slipped a half dollar into a willing palm—­“if you’ll say nothing until I’ve seen him—­”

He beamed.  “Yes, sah!  You jus’ count on George, sah!”

Downstairs I wondered if I could seal the tongue of the youth who had accommodated me before.  Then I discovered that he had gone off duty.  It would be extremely unlikely that he would be about until the following day.  I smiled and hastened out to the street.

Once in the open air again, I realized the full extent of the risk I had taken.  All at once it struck me that no amount of explanation from either Kennedy or myself would serve to mollify Werner if he were innocent and learned of my visit.  I doubted, in this moment of afterthought, that I would escape censure from Kennedy, who surely would not want his case jeopardized by precipitate actions upon my part.  I began to run, to get away from the Whistler Studios as fast as possible.

Then I saw I had grown panicky and I checked myself.  But I hurried to the Subway and up to the university again, and to the laboratory, eager to compare notes with Kennedy.

“If I were Alphonse Dupin,” he remarked, calmly, grasping my excitement, “I would deduce that you have discovered something.  I would also deduce that you believe it important and that you have no intention of withholding the information from me, whatever it is.”

“Correct,” I answered, grinning in spite of myself.

Then I handed him the needle, telling him in a few brief words of my visit to Werner’s apartment, of the hallboy’s confirmation of a nocturnal trip of some sort, of my search of the desk and some other parts of the suite.  “I fixed it so that he won’t hear of my visit, at least for some time.  He won’t suspect who it was, in any case.”