at a point just above the sweep of limehouse reach a watchful river police patrol observed a moving speck of light on the right bank of the thames. as if in answer to the signal there came a few moments later a second moving speck at a point not far above the district once notorious in its possession of ratcliff highway. a third light answered from the surrey bank, and a fourth shone out yet higher up and on the opposite side of the thames.

the tide had just turned. as chief inspector kerry had once observed, “there are no pleasure parties punting about that stretch,” and, consequently, when george martin tumbled into his skiff on the surrey shore and began lustily to pull up stream, he was observed almost immediately by the river police.

pulling hard against the stream, it took him a long time to reach his destination—stone stairs near the point from which the second light had been shown. rain had ceased and the mist had cleared shortly after dusk, as often happens at this time of year, and because the night was comparatively clear the pursuing boats had to be handled with care.

george did not disembark at the stone steps, but after waiting there for some time he began to drop down on the tide, keeping close inshore.

“he knows we've spotted him,” said sergeant coombes, who was in one of the river police boats. “it was at the stairs that he had to pick up his man.”

certainly, the tactics of george suggested that he had recognized surveillance, and, his purpose abandoned, now sought to efface himself without delay. taking advantage of every shadow, he resigned his boat to the gentle current. he had actually come to the entrance of greenwich reach when a dock light, shining out across the river, outlined the boat yellowly.

“he's got a passenger!” said coombes amazedly.

inspector white, who was in charge of the cutter, rested his arm on coombes' shoulder and stared across the moving tide.

“i can see no one,” he replied. “you're over anxious, detective-sergeant—and i can understand it!”

coombes smiled heroically.

“i may be over anxious, inspector,” he replied, “but if i lost sin sin wa, the river police had never even heard of him till the c.i.d. put 'em wise.”

“h'm!” muttered the inspector. “d'you suggest we board him?”

“no,” said coombes, “let him land, but don't trouble to hide any more. show him we're in pursuit.”

no longer drifting with the outgoing tide, george martin had now boldly taken to the oars. the river police boat close in his wake, he headed for the blunt promontory of the isle of dogs. the grim pursuit went on until:

“i bet i know where he's for,” said coombes.

“so do i,” declared inspector white; “dougal's!”

their anticipations were realized. to the wooden stairs which served as a water-gate for the establishment on the isle of dogs, george martin ran in openly; the police boat followed, and:

“you were right!” cried the inspector, “he has somebody with him!”

a furtive figure, bearing a burden upon its shoulder, moved up the slope and disappeared. a moment later the police were leaping ashore. george deserted his boat and went running heavily after his passenger.

“after them!” cried coombes. “that's sin sin wa!”

around the mazey, rubbish-strewn paths the pursuit went hotly. in sight of dougal's coombes saw the swing door open and a silhouette—that of a man who carried a bag on his shoulder—pass in. george martin followed, but the scotland yard man had his hand upon his shoulder.

“police!” he said sharply. “who's your friend?”

george turned, red and truculent, with clenched fists.

“mind your own bloody business!” he roared.

“mind yours, my lad!” retorted coombes warningly. “you're no thames waterman. who's your friend?”

“wotcher mean?” shouted george. “you're up the pole or canned you are!”

“grab him!” said coombes, and he kicked open the door and entered the saloon, followed by inspector white and the boat's crew.

as they appeared, the inspector conspicuous in his uniform, backed by the group of river police, one of whom grasped george martin by his coat collar:

“splits!” bellowed dougal in a voice like a fog-horn.

twenty cups of tea, coffee and cocoa, too hot for speedy assimilation, were spilled upon the floor.

the place as usual was crowded, more particularly in the neighborhood of the two stoves. here were dock laborers, seamen and riverside loafers, lascars, chinese, arabs, negroes and dagoes. mrs. dougal, defiant and red, brawny arms folded and her pose as that of one contemplating a physical contest, glared from behind the “solid” counter. dougal rested his hairy hands upon the “wet” counter and revealed his defective teeth in a vicious snarl. many of the patrons carried light baggage, since a p and o boat, an oriental, and the s. s. mahratta, were sailing that night or in the early morning, and dougal's was the favorite house of call for a doch-an-dorrich for sailormen, particularly for sailormen of color.

upon the police group became focussed the glances of light eyes and dark eyes, round eyes, almond-shaped eyes, and oblique eyes. silence fell.

“we are police officers,” called coombes formally. “all papers, please.”

thereupon, without disturbance, the inspection began, and among the papers scrutinized were those of one, chung chow, an able-bodied chinese seaman. but since his papers were in order, and since he possessed two eyes and wore no pigtail, he excited no more interest in the mind of detective-sergeant coombes than did any one of the other chinamen in the place.

a careful search of the premises led to no better result, and george martin accounted for his possession of a considerable sum of money found upon him by explaining that he had recently been paid off after a long voyage and had been lucky at cards.

the result of the night's traffic, then, spelled failure for british justice, the s.s. mahratta sailed one stewardess short of her complement; but among the chinese crew of another steamer eastward bound was one, chung chow, formerly known as sin sin wa. and sometimes in the night watches there arose before him the picture of a black bird resting upon the knees of an aged chinaman. beyond these figures dimly he perceived the paddy-fields of ho-nan and the sweeping valley of the yellow river, where the opium poppy grows.

it was about an hour before the sailing of the ship which numbered chung chow among the yellow members of its crew that seton pasha returned once more to the deserted wharf whereon he had found mrs. monte irvin's spaniel. afterwards, in the light of ascertained facts, he condemned himself for a stupidity passing the ordinary. for while he had conducted a careful search of the wharf and adjoining premises, convinced that there was a cellar of some kind below, he had omitted to look for a water-gate to this hypothetical cache.

perhaps his self-condemnation was deserved, but in justice to the agent selected by lord wrexborough, it should be added that chief inspector kerry had no more idea of the existence of such an entrance, and exit, than had seton pasha.

leaving the dog at leman street then, and learning that there was no news of the missing chief inspector, seton had set out once more. he had been informed of the mysterious signals flashed from side to side of the lower pool, and was hourly expecting a report to the effect that sin sin wa had been apprehended in the act of escaping. that sin sin wa had dropped into the turgid tide from his underground hiding-place, and pushing his property—which was floatable—before him, encased in a waterproof bag, had swum out and clung to the stern of george martin's boat as it passed close to the empty wharf, neither seton pasha nor any other man knew—except george martin and sin sin wa.

at a suitably dark spot the chinaman had boarded the little craft, not without difficulty, for his wounded shoulder pained him, and had changed his sodden attire for a dry outfit which awaited him in the locker at the stern of the skiff. the cunning of the chinese has the simplicity of true genius.

not two paces had seton taken on to the mystifying wharf when:

“sam tuk barber! entrance in cellar!” rapped a ghostly, muffled voice from beneath his feet. “sam tuk barber! entrance in cellar!”

seton pasha stood still, temporarily bereft of speech. then, “kerry!” he cried. “kerry! where are you?”

but apparently his voice failed to reach the invisible speaker, for:

“sam tuk barber! entrance in cellar!” repeated the voice.

seton pasha wasted no more time. he ran out into the narrow street. a man was on duty there.

“call assistance!” ordered seton briskly, “send four men to join me at the barber's shop called sam tuk's! you know it?”

“yes, sir; i searched it with chief inspector kerry.”

the note of a police whistle followed.

ten minutes later the secret of sam tuk's cellar was unmasked. the place was empty, and the subterranean door locked; but it succumbed to the persistent attacks of axe and crowbar, and seton pasha was the first of the party to enter the vault. it was laden with chemical fumes....

he found there an aged chinaman, dead, seated by a stove in which the fire had burned very low. sprawling across the old man's knees was the body of a raven. lying at his feet was a woman, lithe, contorted, the face half hidden in masses of bright red hair.

“end case near the door!” rapped the voice of kerry. “slides to the left!”

seton pasha vaulted over the counter, drew the shelves aside, and entered the inner room.

by the dim light of a lantern burning upon a moorish coffee-table he discerned an untidy bed, upon which a second woman lay, pallid.

“god!” he muttered; “this place is a morgue!”

“it certainly isn't healthy!” said an irritable voice from the floor. “but i think i might survive it if you could spare a second to untie me.”

kerry's extensive practice in chewing and the enormous development of his maxillary muscles had stood him in good stead. his keen, strong teeth had bitten through the extemporized gag, and as a result the tension of the handkerchief which had held it in place had become relaxed, enabling him to rid himself of it and to spit out the fragments of filthy-tasting wood which the biting operation had left in his mouth.

seton turned, stooped on one knee to release the captive... and found himself looking into the face of someone who sat crouched upon the divan behind the chief inspector. the figure was that of an oriental, richly robed. long, slim, ivory hands rested upon his knees, and on the first finger of the right hand gleamed a big talismanic ring. but the face, surmounted by a white turban, was wonderful, arresting in its immobile intellectual beauty; and from under the heavy brows a pair of abnormally large eyes looked out hypnotically.

“my god!” whispered seton, then:

“if you've finished your short prayer,” rapped kerry, “set about my little job.”

“but, kerry—kerry, behind you!”

“i haven't any eyes in my back hair!”

mechanically, half fearfully, seton touched the hands of the crouching oriental. a low moan came from the woman in the bed, and:

“it's kazmah!” gasped seton. “kerry... kazmah is—a wax figure!”

“hell!” said chief inspector kerry.