"you had better wait for us," said bristol to the taxi-man.

"very good, sir. but i shan't be able to take you further back than the brixton garage. you can get another cab there, though."

a clock chimed out—an old-world chime in keeping with the loneliness, the curiously remote loneliness, of the locality. less than five miles from st. paul's are spots whereto, with the persistence of damascus attar, clings the aroma of former days. this iron gateway fronting the old chapel was such a spot.

just within stood a plain-clothes man, who saluted my companion respectfully.

"professor deeping," i began.

the man, with a simple gesture, conveyed the dreadful news.

"dead! dead!" i cried incredulously.

he glanced at bristol.

"the most mysterious case i have ever had anything to do with, sir," he said.

the power of speech seemed to desert me. it was unthinkable that deeping, with whom i had been speaking less than an hour ago, should now be no more; that some malign agency should thus murderously have thrust him into the great borderland.

in that kind of silence which seems to be peopled with whispering spirits we strode forward along the elm avenue. it was very dark where the moon failed to penetrate. the house, low and rambling, came into view, its facade bathed in silver light. two of the visible windows were illuminated. a sort of loggia ran along one side.

on our left, as we made for this, lay a black ocean of shrubbery. it intruded, raggedly, upon the weed-grown path, for neglect was the keynote of the place.

we entered the cottage, crossed the tiny lobby, and came to the study. a man, evidently deeping's servant, was sitting in a chair by the door, his head sunken in his hands. he looked up, haggard-faced.

"my god! my god!" he groaned. "he was locked in, gentlemen! he was locked in; and yet something murdered him!"

"what do you mean?" said bristol. "where were you?"

"i was away on an errand, sir. when i returned, the police were knocking the door down. he was locked in!"

we passed him, entering the study.

it was a museum-like room, lighted by a lamp on the littered table. at first glance it looked as though some wild thing had run amok there. the disorder was indescribable.

"touched nothing, of course?" asked bristol sharply of the officer on duty.

"nothing, sir. it's just as we found it when we forced the door."

"why did you force the door?"

"he rung us up at the station and said that something or somebody had got into the house. it was evident the poor gentleman's nerve had broken down, sir. he said he was locked in his study. when we arrived it was all in darkness—but we thought we heard sounds in here."

"what sort of sounds?"

"something crawling about!"

bristol turned.

"key is in the lock on the inside of the door," he said. "is that where you found it?"

"yes, sir!"

he looked across to where the brass knob of a safe gleamed dully.

"safe locked?"

"yes, sir."

professor deeping lay half under the table, a spectacle so ghastly that i shall not attempt to describe it.

"merciful heavens!" whispered bristol. "he's nearly decapitated!"

i clutched dizzily at the mantelpiece. it was all so utterly, incredibly horrible. how had deeping met his death? the windows both were latched and the door had been locked from within!

"you searched for the murderer, of course?" asked bristol.

"you can see, sir," replied the officer, "that there isn't a spot in the room where a man could hide! and there was nobody in here when we forced the door!"

"why!" cried my companion suddenly. "the professor has a chisel in his hand!"

"yes. i think he must have been trying to prise open that box yonder when he was attacked."

bristol and i looked, together, at an oblong box which lay upon the floor near the murdered man. it was a kind of small packing case, addressed to professor deeping, and evidently had not been opened.

"when did this arrive?" asked bristol. lester, the professor's man, who had entered the room, replied shakily—

"it came by carrier, sir, just before i went out."

"was he expecting it?"

"i don't think so."

inspector bristol and the officer dragged the box fully into the light. it was some three feet long by one foot square, and solidly constructed.

"it is perfectly evident," remarked bristol, "that the murderer stayed to search for—"

"the key of the safe!"

"exactly. if the men really heard sounds here, it would appear that the assassin was still searching at that time."

"i assure you," the officer interrupted, "that there was no living thing in the room when we entered."

bristol and i looked at one another in horrified wonder.

"it's incomprehensible!" he said.

"see if the key is in the place mentioned by the professor, mr. cavanagh, whilst i break the box."

i went to a great, open bookcase, which the frantic searcher seemed to have overlooked. removing the bulky "assyrian mythology," there, behind the volume, lay an envelope, containing a key, and a short letter. not caring to approach more closely to the table and to that which lay beneath it, i was peering at the small writing, in the semi-gloom by the bookcase, when bristol cried—

"this box is unopenable by ordinary means! i shall have to smash it!"

at his words, i joined him where he knelt on the floor. mysteriously, the chest had defied all his efforts.

"there's a pick-axe in the garden," volunteered lester. "shall i bring it?"

"yes."

the man ran off.

"i see the key is safe," said bristol. "possibly the letter may throw some light upon all this."

"let us hope so," i replied. "you might read it."

he took the letter from my hand, stepped up to the table, and by the light of the lamp read as follows—

my dear cavanagh,—

it has now become apparent to me that my life is in imminent danger. you know of the inexplicable outrages which marked my homeward journey, and if this letter come to your hand it will be because these have culminated in my death.

the idea of a pursuing scimitar is not new to me. this phenomenon, which i have now witnessed three times, is fairly easy of explanation, but its significance is singular. it is said to be one of the devices whereby the hashishin warn those whom they have marked down for destruction, and is called, in the east, "the scimitar of hassan."

the hashishin were the members of a moslem secret society, founded in 1090 by one hassan of khorassan. there is a persistent tradition in parts of the orient that this sect still flourishes in assyria, under the rule of a certain hassan of aleppo, the sheikh-al-jebal, or supreme lord of the hashishin. my careful inquiries, however, at the time that i was preparing matter for my "assyrian mythology," failed to discover any trace of such a person or such a group.

i accordingly assumed hassan to be a myth—a first cousin to the ginn. i was wrong. he exists. and by my supremely rash act i have incurred his vengeance, for hassan of aleppo is the self-appointed guardian of the traditions and relics of mohammed. and i have stolen one of the holy slippers of the prophet!

he, with some of his servants, has followed me from mecca to england. my precautions have enabled me to retain the relic, but you have seen what fate befell all those others who even touched the receptacle containing it.

if i fall a victim to the hashishin, i am uncertain how you, as my confidant, will fare. therefore i have locked the slipper in my safe and to you entrust the key. i append particulars of the lock combination; but i warn you—do not open the safe. if their wrath be visited upon you, your possession of the key may prove a safeguard.

take the copy of "assyrian mythology." you will find in it all that i learned respecting the hashishin. if i am doomed to be assassinated, it may aid you; if not in avenging me, in saving others from my fate. i fear i shall never see you again. a cloud of horror settles upon me like a pall. do not touch the slipper, nor the case containing it.

edward deeping.

"it is almost incredible!" i said hoarsely.

bristol returned the letter to me without a word, and turning to lester, who had reentered carrying a heavy pick-axe, he attacked the oblong box with savage energy.

through the house of death the sound of the blows echoed and rang with a sort of sacrilegious mockery. the box fell to pieces.

"my god! look, sir!"

lester was the trembling speaker.

the box, i have said, was but three feet long by one foot square, and had clearly defied poor deeping's efforts to open it. but a crescent-shaped knife, wet with blood, lay within!