my ghastly duty was performed; i had identified the dreadful thing, which less than an hour before had been a strikingly beautiful woman, as my mysterious visitor. the police were palpably disappointed at the sparsity of my knowledge respecting her. in fact, had it not chanced that detective sergeant durham was in the station, i think they would have doubted the accuracy of my story.

as a man of some experience in such matters, i fully recognized its improbability, but beyond relating the circumstances leading up to my possession of the pigtail and the events which had ensued, i could do no more in the matter. the weird relic had not been found on the dead woman, nor in the cab.

now the unsavoury business was finished, and i walked along bow street, racking my mind for the master-key to this mystery in which i was become enmeshed. how i longed to rush off to harley's rooms in chancery lane and to tell him the whole story! but my friend was a thousand miles away—and i had to see the thing out alone.

that the pigtail was some sacred relic stolen from a chinese temple and sought for by its fanatical custodians was a theory which persistently intruded itself. but i could find no place in that hypothesis for the beautiful jewess; and that she was intimately concerned i did not doubt. a cool survey of the facts rendered it fairly evident that it was she and none other who had stolen the pigtail from my rooms. some third party—possibly the “yellow man” of whom she had spoken—had in turn stolen it from her, strangling her in the process.

the police theory of the murder (and i was prepared to accept it) was that the assassin had been crouching in hiding behind or beside the cab—or even within the dark interior. he had leaped in and attacked the woman at the moment that the taxi-man had started his engine; if already inside, the deed had proven even easier. then, during some block in the traffic, he had slipped out unseen, leaving the body of the victim to be discovered when the cab pulled up at the hotel.

i knew of only one place in london where i might hope to obtain useful information, and for that place i was making now. it was malay jack's, whence i had been bound on the previous night when my strange meeting with the seaman who then possessed the pigtail had led to a change of plan. the scum of the asiatic population always come at one time or another to jack's, and i hoped by dint of a little patience to achieve what the police had now apparently despaired of achieving—the discovery of the assassin.

having called at my chambers to obtain my revolver, i mounted an eastward-bound motor-bus. the night, as i have already stated, was exceptionally dark. there was no moon, and heavy clouds were spread over the sky; so that the deserted east end streets presented a sufficiently uninviting aspect, but one with which i was by no means unfamiliar and which certainly in no way daunted me.

changing at paul harley's chinatown base in wade street, i turned my steps in the same direction as upon the preceding night; but if my own will played no part in the matter, then decidedly providence truly guided me. poetic justice is rare enough in real life, yet i was destined to-night to witness swift retribution overtaking a malefactor.

the by-ways which i had trodden were utterly deserted; i was far from the lighted high road, and the only signs of human activity that reached me came from the adjacent river; therefore, when presently an outcry arose from somewhere on my left, for a moment i really believed that my imagination was vividly reproducing the episode of the night before!

a furious scuffle—between a european and an asiatic—was in progress not twenty yards away!

realizing that such was indeed the case, and that i was not the victim of hallucination, i advanced slowly in the direction of the sounds, but my footsteps reechoed hollowly from wall to wall of the narrow passage-way, and my coming brought the conflict to a sudden and dramatic termination.

“thought i wouldn't know yer ugly face, did yer?” yelled a familiar voice. “no good squealin'—i got yer! i'd bust you up if i could!” (a sound of furious blows and inarticulate chattering) “but it ain't 'umanly possible to kill a chink———”

i hurried forward toward the spot where two dim figures were locked in deadly conflict.

“take that to remember me by!” gasped the husky voice as i ran up.

one of the figures collapsed in a heap upon the ground. the other made off at a lumbering gait along a second and even narrower passage branching at right angles from that in which the scuffle had taken place.

the clatter of the heavy sea-boots died away in the distance. i stood beside the fallen man, looking keenly about to right and left; for an impression was strong upon me that another than i had been witness of the scene—that a shadowy form had slunk back furtively at my approach. but the night gave up no sound in confirmation of this, and i could detect no sign of any lurker.

i stooped over the chinaman (for a chinaman it was) who lay at my feet, and directed the ray of my pocket-lamp upon his yellow and contorted countenance. i suppressed a cry of surprise and horror.

despite the human impossibility referred to by the missing fireman, this particular chinaman had joined the shades of his ancestors. i think that final blow, which had felled him, had brought his shaven skull in such violent contact with the wall that he had died of the thundering concussion set up.

kneeling there and looking into his upturned eyes, i became aware that my position was not an enviable one, particularly since i felt little disposed to set the law on the track of the real culprit. for this man who now lay dead at my feet was doubtless one of the pair who had attempted the life of the fireman of the jupiter.

that my seafaring acquaintance had designed to kill the chinaman i did not believe, despite his stormy words: the death had been an accident, and (perhaps my morality was over-broad) i considered the assault to have been justified.

now my ideas led me further yet. the dead chinaman wore a rough blue coat, and gingerly, for i found the contact repulsive, i inserted my hand into the inside pocket. immediately my fingers closed upon a familiar object—and i stood up, whistling slightly, and dangling in my left hand the missing pigtail!

beyond doubt justice had guided the seaman's blows. this was the man who had murdered my dark-eyed visitor!

i stood perfectly still, directing the little white ray of my flashlight upon the pigtail in my hand. i realized that my position, difficult before, now was become impossible; the possession of the pigtail compromised me hopelessly. what should i do?

“my god!” i said aloud, “what does it all mean?”

“it means,” said a gruff voice, “that it was lucky i was following you and saw what happened!”

i whirled about, my heart leaping wildly. detective-sergeant durham was standing watching me, a grim smile upon his face!

i laughed rather shakily.

“lucky indeed!” i said. “thank god you're here. this pigtail is a nightmare which threatens to drive me mad!”

the detective advanced and knelt beside the crumpled-up figure on the ground. he examined it briefly, and then stood up.

“the fact that he had the missing pigtail in his pocket,” he said, “is proof enough to my mind that he did the murder.”

“and to mine.”

“there's another point,” he added, “which throws a lot of light on the matter. you and mr. harley were out of town at the time of the huang chow case; but the chief and i outlined it, you remember, one night in mr. harley's rooms?”

“i remember it perfectly; the giant spider in the coffin———”

“yes; and a certain ah fu, confidential servant of the old man, who used to buy the birds the thing fed on. well, mr. knox, huang chow was the biggest dealer in illicit stuff in all the east end—and this battered thing at our feet is—ah fu!”

“huang chow's servant?”

“exactly!”

i stared, uncomprehendingly, and:

“in what way does this throw light on the matter?” i asked.

durham—a very intelligent young officer—smiled significantly.

“i begin to see light!” he declared. “the gentleman who made off just as i arrived on the scene probably had a private quarrel with the chinaman and was otherwise not concerned in any way.”

“i am disposed to agree with you,” i said guardedly.

“of course, you've no idea of his identity?”

“i'm afraid not.”

“we may find him,” mused the officer, glancing at me shrewdly, “by applying at the offices of the planet line, but i rather doubt it. also i rather doubt if we'll look very far. he's saved us a lot of trouble, but”—peering about in the shadowy corners which abounded—“didn't i see somebody else lurking around here?”

“i'm almost certain there was someone else!” i cried. “in fact, i could all but swear to it.”

“h'm!” said the detective. “he's not here now. might i trouble you to walk along to limehouse police station for the ambulance? i'd better stay here.”

i agreed at once, and started off.

thus a second time my plans were interrupted, for my expedition that night ultimately led me to bow street, whence, after certain formalities had been observed, i departed for my chambers, the mysterious pigtail in my pocket. failing the presence of durham, the pigtail must have been retained as evidence, but:

“we shall know where to find it if it's wanted, mr. knox,” said the yard man, “and i can trust you to look after your own property.”

the clock of st. paul's was chiming the hour of two when i locked the door of my chambers and prepared to turn in. the clangour of the final strokes yet vibrated through the night's silence when someone set my own door bell loudly ringing.

with an exclamation of annoyance i shot back the bolts and threw open the door.

a chinaman stood outside upon the mat!