“I understand very well, Cavanagh!” he replied.  “You will recall my story of the scimitar which flashed before me in the darkness of my stateroom on the Mandalay?  Well, I have seen it again!  I am not an imaginative man:  I had always believed myself to possess the scientific mind; but I can no longer doubt that I am the object of a pursuit which commenced in Mecca!  The happenings on the steamer prepared me for this, in a degree.  When the man lost his hand at Port Said I doubted.  I had supposed the days of such things past.  The attempt to break into my stateroom even left me still uncertain.  But the outrage upon the steward at the docks removed all further doubt.  I perceived that the contents of a certain brown leather case were the objective of the crimes.”

I listened in growing wonder.

“It was not necessary in order to further the plan of stealing the bag that the hands were severed,” resumed the Professor.  “In fact, as was rendered evident by the case of the steward, this was a penalty visited upon any one who touched it!  You are thinking of my own immunity?”

“I am!”

“This is attributable to two things.  Those who sought to recover what I had in the case feared that my death en route might result in its being lost to them for ever.  They awaited a suitable opportunity.  They had designed to take it at Port Said certainly, I think; but the bag was too large to be readily concealed, and, after the outrage, might have led to the discovery of the culprit.  In the second place, they are uncertain of my faith.  I have long passed for a true Believer in the East!  As a Moslem I visited Mecca—­”

“You visited Mecca!”

“I had just returned from the hadj when I joined the Mandalay at Port Said!  My death, however, has been determined upon, whether I be Moslem or Christian!”

“Why?”

“Because,” came the Professor’s harsh voice over the telephone, “of the contents of the brown leather case!  I will not divulge to you now the nature of these contents; to know might endanger you.  But the case is locked in my safe here, and the key, together with a full statement of the true facts of the matter, is hidden behind the first edition copy of my book ‘Assyrian Mythology,’ in the smaller bookcase—­”

“Why do you tell me all this?” I interrupted.

He laughed harshly.

“The identity of my pursuer has just dawned upon me,” he said.  “I know that my life is in real danger.  I would give up what is demanded of me, but I believe its possession to be my strongest safeguard.”

Mystery upon mystery!  I seemed to be getting no nearer to the heart of this maze.  What in heaven’s name did it all mean?  Suddenly an idea struck me.

“Is our late fellow passenger, Mr. Ahmadeen, connected with the matter?” I asked.

“In no way,” replied Deeping earnestly.  “Mr. Ahmadeen is, I believe, a person of some consequence in the Moslem world; but I have nothing to fear from him.”