i stood in the foyer of the astoria hotel. about me was the pulsing stir of transatlantic life, for the tourist season was now at its height, and i counted myself fortunate in that i had been able to secure a room at this establishment, always so popular with american visitors. chatting groups surrounded me and i became acquainted with numberless projects for visiting the tower of london, the national gallery, the british museum, windsor castle, kew gardens, and the other sights dear to the heart of our visiting cousins. loaded lifts ascended and descended. bradshaws were in great evidence everywhere; all was hustle and glad animation.

the tall military-looking man who stood beside me glanced about him with a rather grim smile.

"you ought to be safe enough here, mr. cavanagh!" he said.

"i ought to be safe enough in my own chambers," i replied wearily. "how many of these pleasure-seeking folk would believe that a man can be as greatly in peril of his life in fleet street as in the most uncivilized spot upon the world map? do you think if i told that prosperous new yorker who is buying a cigar yonder, for instance, that i had been driven from my chambers by a band of eastern assassins founded some time in the eleventh century, he would believe it?"

"i am certain he wouldn't!" replied bristol. "i should not have credited it myself before i was put in charge of this damnable case."

my position at that hour was in truth an incredible one. the sacred slipper of mohammed lay once more in the glass case at the antiquarian museum from which earl dexter had stolen it. now, with apish yellow faces haunting my dreams, with ghostly menaces dogging me day and night, i was outcast from my own rooms and compelled, in self-defence, to live amid the bustle of the astoria. so wholly nonplussed were the police authorities that they could afford me no protection. they knew that a group of scientific murderers lay hidden in or near to london; they knew that earl dexter, the foremost crook of his day, was also in the metropolis—and they could make no move, were helpless; indeed, as bristol had confessed, were hopeless!

bristol, on the previous day, had unearthed the greek cigar merchant, acepulos, who had replaced the slipper in its case (for a monetary consideration). he had performed a similar service when the bloodstained thing had first been put upon exhibition at the museum, and for a considerable period had disappeared. we had feared that his religious pretensions had not saved him from the avenging scimitar of hassan; but quite recently he had returned again to his soho shop, and in time thus to earn a second cheque.

as bristol and i stood glancing about the foyer of the hotel, a plain-clothes officer whom i knew by sight came in and approached my companion. i could not divine the fact, of course, but i was about to hear news of the money-loving and greatly daring graeco-moslem.

the detective whispered something to bristol, and the latter started, and paled. he turned to me.

"they haven't overlooked him this time, mr. cavanagh," he said. "acepulos has been found dead in his room, nearly decapitated!"

i shuddered involuntarily. even there, amid the chatter and laughter of those light-hearted tourists, the shadow of hassan of aleppo was falling upon me.

bristol started immediately for soho and i parted from him in the strand, he proceeding west and i eastward, for i had occasion that morning to call at my bank. it was the time of the year when london is full of foreigners, and as i proceeded in the direction of fleet street i encountered more than one oriental. to my excited imagination they all seemed to glance at me furtively, with menacing eyes, but in any event i knew that i had little to fear whilst i contrived to keep to the crowded thoroughfares. solitude i dreaded and with good reason.

then at the door of the bank i found fresh matter for reflection. the assistant manager, mr. colby, was escorting a lady to the door. as i stood aside, he walked with her to a handsome car which waited, and handed her in with marks of great deference. she was heavily veiled and i had no more than a glimpse of her, but she appeared to be of middle age and had gray hair and a very stately manner.

i told myself that i was unduly suspicious, suspicious of everyone and of everything; yet as i entered the bank i found myself wondering where i had seen that dignified, grayhaired figure before. i even thought of asking the manager the name of his distinguished customer, but did not do so, for in the circumstances such an inquiry must have appeared impertinent.

my business transacted, i came out again by the side entrance which opens on the little courtyard, for this branch of the london county and provincial bank occupies a corner site.

a ragged urchin who was apparently waiting for me handed me a note. i looked at him inquiringly.

"for me?" i said.

"yes, sir. a dark gentleman pointed you out as you was goin' into the bank."

the note was written upon a half sheet of paper and, doubting if it was really intended for me, i unfolded it and read the following—

mr. cavanagh, take the keys of the case containing the holy slipper to your hotel this evening without fail.

hassan.

"who gave you this, boy?" i asked sharply.

"a foreign gentleman, sir, very dark—like an indian."

"where is he?"

"he went off in a cab, sir, after he give me the note."

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.

again i doubted the wisdom of bristol's plan. had i not fled to the astoria to escape from the dangerous solitude of my rooms? that he was laying some trap for the hashishin was sufficiently evident, and whilst i could not justly suspect him of making a pawn of me i was quite unable to find any other explanation of this latest move.

i was torn between conflicting doubts. i glanced at my watch. yes! there was just time for me to revisit the bank ere joining bristol at my chambers! i hesitated. after all, in what possible way could it jeopardize his plans for me merely to pretend to bring the keys?

"hang it all!" i said, and jumped to my feet. "these maddening conjectures will turn my brain! i'll let matters stand as they are, and risk the consequences!"

i hesitated no longer, but passed out from the hotel and once more directed my steps in the direction of fleet street.

as i passed in under the arch through which streamed many busy workers, i told myself that to dread entering my own chambers at high noon was utterly childish. yet i did dread doing so! and as i mounted the stair and came to the landing, which was always more or less dark, i paused for quite a long time before putting the key in the lock.

the affair of the accursed slipper was playing havoc with my nerves, and i laughed dryly to note that my hand was not quite steady as i turned the key, opened my door, and slipped into the dim hallway.

as i closed it behind me, something, probably a slight noise, but possibly something more subtle—an instinct—made me turn rapidly.

there facing me stood hassan of aleppo.