He did not finish the sentence, but left it to my imagination.  It was my turn, now, to remain silent.

“You are right, though, Tom, in one respect,” he resumed a moment later.  “It is not easy by the old methods that everyone now knows.  For instance, take the use of chloral-knock-out drops, you know.  That is crude, too.  Hypodermics and knock-out drops may answer well enough, perhaps, for the criminals whose victims are found in cafes and dives of a low order.  But for the operations of an aristocratic criminal of to-day—­and our friend the Chief seems to belong to the aristocracy of the underworld—­far more subtle methods are required.  Let me show you something.”

Carefully, from the back of a drawer in the cabinet, where it was concealed in a false partition, he pulled out a little case.  He opened it, and in it displayed a number of tiny globes and tubes of thin glass, each with a liquid in it, some lozenges, some bonbons, and several cigars and cigarettes.

“I’m doing this,” he remarked, “to show you, Tom, that I’m not unduly magnifying the danger that surrounds Violet Winslow, after hearing what I did over that detectaphone.  Perhaps it didn’t impress you, but I think I know something of what we’re up against.”

From another part of the case he drew a peculiar looking affair and handed to me without a word.  It consisted of a glass syringe about two inches long, fitted with a glass plunger and an asbestos washer.  On the other end of the tube was a hollow point, about three-eighths of an inch long—­just a shiny little bit of steel such as he had already showed me.

I looked at it curiously and, in spite of my former assurance, began to wonder whether, after all, the possibility of a girl being struck down suddenly, without warning, in a public place and robbed—­or worse—­might not take on the guise of ghastly reality.

“What do you make of it?” asked Garrick, evidently now enjoying the puzzled look on my face.

I could merely shrug my shoulders.

“Well,” he drawled, “that is a weapon they hinted at last night.  The possibilities of it are terrifying.  Why, it could easily be plunged through a fur coat, without breaking.”

He took the needle and made an imaginary lunge at me.

“When people tell you that the hypodermic needle cannot be employed in a case like this that they are planning,” he continued, “they are thinking of ordinary hypodermics.  Those things wouldn’t be very successful usually, anyhow, under such circumstances.  But this is different.  The very form of this needle makes it particularly effective for anyone who wishes to use it for crime.  For instance—­take it on a railroad or steamship or in a hotel.  Draw back the plunger—­so—­one quick jab—­then drop it on the floor and grind it under your heel.  The glass is splintered into a thousand bits.  All evidence of guilt is destroyed, unless someone is looking for it practically with a microscope.”