“I wonder,” I said.  I stepped into the room.  But I hadn’t counted on the dog.  With a yelp she was upon me, had me by the calf of the leg and was drawing me back.  She stepped in front of me; a low, guttural growl of warning.  But there was nothing in that room; of that we were certain.

“Beats me,” said the detective.  “How does she know?  Wonder if she would stop me?” He stepped forward.  It was merely a repetition.  She caught him by the trouser-leg and drew him back.  She crowded us away from the curtain.  It was almost magnetic.  We could see nothing, neither could we feel; was it possible that the dog could see beyond us?  The detective spoke first: 

“Take her out of the room.  Put her in the hall; tie her up.”

“What’s the idea?”

“Merely this; I am going to examine the room.  No, I am not afraid.  I’ll be mighty glad if it does catch me.  Anything so long as I get results.”

But it did us no good.  We examined the room many times that night; both of us.  In the end there was nothing, only the weirdness and uncertainty and the magnetic undercurrent which we could feel, but could not fathom.  When we called in the dog she stepped to the portieres and commenced her vigil.  She crouched slightly behind the curtains, alert, ready, waiting, at her post of honour.  From that moment she never left the spot except under compulsion.  We could hear her at all times of the night; the low growl, the snarl, the defiance.

But there was a great deal more that we were to learn from the dog.  It was Jerome who first called my attention.  A small fact at the beginning; but of a strange sequence.  This time it was the ring.  Queen had the habit that is common to most dogs; she would lick my hand to show her affection.  It was nothing in itself; but for one fact—­she always chose the left hand.  It was the detective who first noticed it.  Always and every opportunity she would lick the jewel.  We made a little test to try her.  I would remove the ring from one hand to the other; then hold it behind me.  She would follow.

It was a strange fact; but of course not inexplicable.  A scent or the attraction of taste might account for it.  However, these little tests led to a rather remarkable discovery.

One night we had called the dog from her vigil.  As usual she came to the jewel; by chance I pressed the gem against her head.  It was a mere trifle; yet it was of consequence.  A few minutes before I had dropped a handkerchief on the opposite side of the room; I was just thinking about picking it up.  It was only a small thing, yet it put us on the track of the gem’s strangest potency.  The dog walked to the handkerchief.  She brought it back in her mouth.  At first I took it for a pure coincidence.  I repeated the experiment with a book.  The same result.  I looked up at Jerome.

“What’s the matter?” Then when I explained:  “The dickens!  Try it again.”