the archway; she crossed the
courtyard--and is upon the stair! Admit her, effendim; I shall be close
behind you!"

The door-bell rang.

With the consciousness that the black tube was directed toward the
back of my head, I went and opened the door. My mind was at work
again, and busy with plans to terminate this impossible situation.

On the landing stood a girl wearing a simple white frock which
fitted her graceful figure perfectly. A white straw hat, of the New
York tourist type, with a long veil draped from the back suited her
delicate beauty very well. The red mouth drooped a little at the
corners, but the big violet eyes, like lamps of the soul, seemed
afire with mystic light.

"Mr. Cavanagh," she said, very calmly and deliberately, "there is
only one way now to end all this trouble. I come from the man who
can return the slipper to where it belongs; but he wants his price!"

Her quiet speech served completely to restore my mental balance, and
I noted with admiration that her words were so chosen as to commit
her in no way. She knew quite well that thus far she might appear
in the matter with impunity, and she clearly was determined to say
nothing that could imperil her.

"Will you please come in?" I said quietly--and stood aside to
admit her.

Exhibiting wonderful composure, she entered--and there, in the
badly lighted hallway came face to face with my other visitor!

It was a situation so dramatic as to seem unreal.

Away from that tall figure retreated the girl with the violet
eyes--and away--until she stood with her back to the wall. Even in
the gloom I could see that her composure was deserting her; her
beautiful face was pallid.

"Oh, God!" she whispered, all but inaudible--"You!"

Hassan, grasping the black rod in his hand, signed to her to enter
the study. She stood quite near to me, with her eyes fixed upon
him. I bent closer to her.

"My revolver--in left-hand table drawer," I breathed in her ear.
"Get it. He is watching me!"

I could not tell if my words had been understood, for, never taking
her gaze from the Sheikh of the Assassins, she sidled into the study.
I followed her; and Hassan came last of all. Just within the
doorway he stood, confronting us.

"You have come," he said, addressing the girl and speaking in
perfect English but with a marked accent, "to open your impudent
negotiations through Mr. Cavanagh for the return of the thrice holy
relic to the Museum! Your c