detective durham, as he lay there inhaling the peculiar perfume of the place, recognized that he had put himself outside the pale of official protection, and was become technically a burglar.

he wondered if chief inspector kerry would have approved; but he had outlined this plan of investigation for himself, and knew well that, if it were crowned by success, the end would be regarded as having justified the means. on the other hand, in the event of detention he must personally bear the consequences of such irregular behaviour. he knew well, however, that his celebrated superior had achieved promotion by methods at least as irregular; and he knew that if he could but obtain evidence to account for the death of the man cohen, and of the chinaman pi lung, who had preceded him by the same mysterious path, the way of his obtaining it would not be too closely questioned.

he was an ambitious man, and consequently one who took big chances. nothing disturbed the silence; he sat upon the divan and again pressed the button of his torch, shining it all about the low-beamed apartment and peering curiously into the weird shadows of the place. he calculated he was now in the position which cohen had occupied during the last moments of his life, and a sense of the uncanny touched him coldly.

as he thought of the unnatural screams spoken of by poland, some strange instinct prompted him to curl up his feet upon the divan again, as though a secret menace crawled upon the floor amid its many rugs and carpets.

he must now endeavour to reconstruct the plan upon which the american cracksman had operated. poland had a persistent belief that cohen had known where the fabled hoard of huang chow was concealed.

durham began a deliberate inspection of the place. he thought it unlikely that a wily old chinaman, assuming that he possessed hidden wealth, would keep it in so accessible a spot as this. it was far more probable that he had a fireproof safe in the room upstairs, perhaps built into the wall. yet, according to poland's account, it was in this room and not in any other that death came to diamond fred.

the wall-hangings first engaged durham's attention. he moved them aside systematically, one after another, seeking for any hiding-place, but failing to find one. the door communicating with the outer office he found to be locked, but he did not believe for a moment that the office would be worthy of inspection.

there were cases containing jewelled weapons and cups and goblets inlaid with precious stones, but none of these seemed to have been tampered with, and all were locked, as was the big cabinet filled with snuff bottles.

many of the larger pieces about the place contained drawers and cupboards, and these he systematically opened one after another, without making any discovery of note. some of the cupboards contained broken pieces of crockery, and more or less damaged curios of one kind and another, but none of them gave him the clue for which he was seeking.

he examined the couch upon which huang chow had been seated when first he had met him, but although he searched it scientifically he was rewarded by no discovery.

a very fusty and unpleasant smell was more noticeable at this point than elsewhere in the room, and he found himself staring speculatively up the wide, carpeted stairs. next he turned his attention to the lacquered coffin which occupied the corresponding recess to that filled by the couch. it was an extraordinarily ornate piece of lacquer work and probably of great value.

the lid appeared to be screwed on, and durham stood staring at the thing, half revolted and half fascinated. he failed to discover any means of opening it, however, and when he tried to move it bodily found it very heavy. he came to the conclusion that all the portable valuables were contained in locked cases or cabinets, and out of this discovery grew an idea.

the case containing the snuff bottles stood too close to the wall to enable him to test his new theory, but a square case near the office door, in which were five of six small but almost priceless pieces of porcelain, afforded the very evidence for which he was looking.

thin electric flex descended from somewhere inside the case down one of the legs of the pedestal, and through a neatly drilled hole in the floor, evidently placed there to accommodate it.

“burglar alarm!” he muttered.

the opening of this case, and doubtless of any of the others, would set alarm bells ringing. this was not an unimportant discovery, but it brought him very little nearer to a solution of the chief problem which engaged his mind. assuming that cohen had opened one of the cases and had alarmed old huang chow, what steps had the latter taken to deal with the intruder which had resulted in so ghastly a death? and how had he disposed of the body?

as durham stood there musing and looking down through the plate-glass at the delicate porcelain beneath, a faint sound intruded itself upon the stillness. it gave him another idea. part of the floor was stone-paved, but part was wood.

upon a portion of the latter, where no carpet rested, durham dropped flat, pressing his ear to the floor.

a faint swishing and trickling sound was perceptible from some place beneath.

“ah!” he murmured.

remembering that the premises almost overhung the thames, he divined that the cellars were flooded at high tide, or that there was some kind of drain or cutting running underneath the house.

he stood up again, listening intently for any sound within the building. he thought he had detected something, and now, as he stood there alert, he heard it again—a faint scuffling, which might have been occasioned by rats or even mice, but which, in some subtle and very unpleasant way, did not suggest the movements of these familiar rodents.

even as he perceived it, it ceased, leaving him wondering, and uncomfortably conscious of a sudden dread of his surroundings. he wondered in what part of this mysterious house lala resided, and recognizing that his departure must leave traces, he determined to prosecute his inquiries as far as possible, since another opportunity might not arise.

he was baffled but still hopeful. something there was in the smell of the place which threatened to unnerve him; or perhaps in its silence, which remained quite unbroken save when, by acute listening, one detected the dripping of water.

that unexplained scuffling sound, too, which he had failed to trace or identify, lingered in his memory insistently, and for some reason contained the elements of fear.

he crossed the room and began softly to mount the stair. it creaked only slightly, and the door at the top proved to be ajar. he peeped in, to find the place empty. it was a typical chinese apartment, containing very little furniture, the raised desk being the most noticeable item, except for a small shrine which faced it on the other side of the room.

he mounted the steps to the desk and inspected a number of loose papers which lay upon it. without exception they were written in chinese. a sort of large, dull white blotting-pad lay upon the table, but its surface was smooth and glossy.

over it was suspended what looked like a lampshade, but on inspection it proved to contain no lamp, but to communicate, by a sort of funnel, with the ceiling above.

at this contrivance durham stared long and curiously, but without coming to any conclusion respecting its purpose. he might have investigated further, but he became aware of a dull and regular sound in the room behind him.

he turned in a flash, staring in the direction of two curtains draped before what he supposed to be a door.

on tiptoe he crossed and gently drew the curtains aside.

he looked into a small, cell-like room, lighted by one window, where upon a low bed huang chow lay sleeping peacefully!

durham almost held his breath; then, withdrawing as quietly as he had approached, he descended the stair. at the foot his attention was again arrested by the faint scuffling sound. it ceased as suddenly as it had begun, leaving him wondering and conscious anew of a chill of apprehension.

he had already made his plans for departure, but knew that they must leave evidence, when discovered, of his visit.

a large and solid table stood near the divan, and he moved this immediately under the trap. upon it he laid a leopard-skin to deaden any noise he might make, and then upon the leopard-skin he set a massive chair: he replaced his torch in his pocket and drew himself up on to the roof again. reclosing the trap by means of the awl which he had screwed into it, he removed the awl and placed it in his pocket.

then, sliding gently down the sloping roof, he dropped back into the deserted court.