I handed the boy sixpence and slowly pursued my way.  An idea was forming in my mind to trap the enemy by seeming acquiescent.  I wondered if my movements were being watched at that moment.  Since it was more than probable, I returned to the bank, entered, and made some trivial inquiry of a cashier, and then came out again and walked on as far as the Report office.

I had not been in the office more than five minutes before I received a telegram from Inspector Bristol.  It had been handed in at Soho, and the message was an odd one.

Cavanagh, Report, London. 
Plot afoot to steal keys.  Get them from bank and join me 11 o’clock
at Astoria.  Have planned trap. 
          
                                                 Bristol.

This was very mysterious in view of the note so recently received by me, but I concluded that Bristol had hit upon a similar plan to that which was forming in my own mind.  It seemed unnecessarily hazardous, though, actually to withdraw the keys from their place of safety.

Pondering deeply upon the perplexities of this maddening case, I shortly afterward found myself again at the bank.  With the manager I descended to the strong-room, and the safe was unlocked which contained the much-sought-for keys of the case at the Antiquarian Museum.

“There are the keys, quite safe!—­and by the way, this is my second visit here this morning, Mr. Cavanagh,” said the manager, with whom I was upon rather intimate terms.  “A foreign lady who has recently become a customer of the bank deposited some valuable jewels here this morning—­less than an hour ago, in fact.”

“Indeed,” I said, and my mind was working rapidly.  “The lady who came in the large blue car, a gray-haired lady?”

“Yes,” was the reply, “did you notice her, then?”

I nodded and said no more, for in truth I had no more to say.  I had good reason to respect the uncanny powers of Hassan of Aleppo, but I doubted if even his omniscience could tell him (since I had actually gone down into the strong-room) whether when I emerged I had the keys, or whether my visit and seeming acceptance of his orders had been no more than a subterfuge!

That the Hashishin had some means of communicating with me at the Astoria was evident from the contents of the note which I had received, and as I walked in the direction of the hotel my mind was filled with all sorts of misgivings.  I was playing with fire!  Had I done rightly or should I have acted otherwise?  I sighed wearily.  The dark future would resolve all my doubts.

When I reached the Astoria, Bristol had not arrived.  I lighted a cigarette and sat down in the lounge to await his coming.  Presently a boy approached, handing me a message which had been taken down from the telephone by the clerk.  It was as follows—­

Tell Mr. Cavanagh, who is waiting in the hotel, to take what I am expecting to his chambers, and say that I will join him there in twenty minutes. 
                                                 Inspector Bristol.