detective-sergeant coombes and three assistants watched the house of sin sin wa, and any one of the three would have been prepared to swear “on the book” that sin sin wa was sleeping. but he who watches a chinaman watches an illusionist. he must approach his task in the spirit of a psychical inquirer who seeks to trap a bogus medium. the great robert houdin, one of the master wizards of modern times, quitted petrograd by two gates at the same hour according to credible witnesses; but his performance sinks into insignificance beside that of a chinese predecessor who flourished under one of the ming emperors. the palace of this potentate was approached by gates, each having twelve locks, and each being watched by twelve guards. nevertheless a distinguished member of the wizard family not only gained access to the imperial presence but also departed again unseen by any of the guards, and leaving all the gates locked behind him! if detective-sergeant coombes had known this story he might not have experienced such complete confidence.

that door of sin sin wa's establishment which gave upon a little backyard was oiled both lock and hinge so that it opened noiselessly. like a shadow, like a ghost, sin sin wa crept forth, closing the door behind him. he carried a sort of canvas kit-bag, so that one observing him might have concluded that he was “moving.”

resting his bag against the end wall, he climbed up by means of holes in the neglected brickwork until he could peer over the top. a faint smell of tobacco smoke greeted him: a detective was standing in the lane below. soundlessly, sin sin wa descended again. raising his bag he lifted it lovingly until it rested upright upon the top of the wall and against the side of the house. the night was dark and still. only a confused beating sound on the surrey bank rose above the murmur of sleeping london.

from the rubbish amid which he stood, sin sin wa selected a piece of rusty barrel-hoop. cautiously he mounted upon a wooden structure built against the end wall and raised himself upright, surveying the prospect. then he hurled the fragment of iron far along the lane, so that it bounded upon a strip of corrugated roofing in a yard twice removed from his own, and fell clattering among a neighbor's rubbish.

a short exclamation came from the detective in the lane. he could be heard walking swiftly away in the direction of the disturbance. and ere he had gone six paces, sin sin wa was bending like an inverted u over the wall and was lowering his precious bag to the ground. like a cat he sprang across and dropped noiselessly beside it.

“hello! who's there?” cried the detective, standing by the wall of the house which sin sin wa had selected as a target.

sin sin wa, bag in hand, trotted, soft of foot, across the lane and into the shadow of the dock-building. by the time that the c.i.d. man had decided to climb up and investigate the mysterious noise, sin sin wa was on the other side of the canal and rapping gently upon the door of sam tuk's hairdressing establishment.

the door was opened so quickly as to suggest that someone had been posted there for the purpose. sin sin wa entered and the door was closed again.

“light, ah fung,” he said in chinese. “what news?”

the boy who had admitted him took a lamp from under a sort of rough counter and turned to sin sin wa.

“george came with the boat, master, but i signalled to him that the red policeman and the agent who has hired the end room were watching.”

“they are gone?”

“they gather men at the head depot and are searching house from house. she who sleeps below awoke and cried out. they heard her cry.”

“george waits?”

“he waits, master. he will wait long if the gain is great.”

“good.”

sin sin wa shuffled across to the cellar stairs, followed by ah fung with the lamp. he descended, and, brushing away the carefully spread coal dust, inserted the piece of bent wire into the crevice and raised the secret trap. bearing his bag upon his shoulder he went down into the tunnel.

“reclose the door, ah fung,” he said softly; “and be watchful.”

as the boy replaced the stone trap, sin sin wa struck a match. then, having the lighted match held in one hand and carrying the bag in the other, he crept along the low passage to the door of the cache. dropping the smouldering match-end, he opened the door and entered that secret warehouse for which so many people were seeking.

seated in a cane chair by the oil-stove was the shrivelled figure of sam tuk, his bald head lolling sideways so that his big horn-rimmed spectacles resembled a figure 8. on the counter was set a ship's lantern. as sin sin wa came in sam tuk slowly raised his head.

no greetings were exchanged, but sin sin wa untied the neck of his kit-bag and drew out a large wicker cage. thereupon: “hello! hello!” remarked the occupant drowsily. “number one p'lice chop lo! sin sin wa—sin sin....”

“come, my tling-a-ling,” crooned sin sin wa.

he opened the front of the cage and out stepped the raven onto his wrist. sin sin wa raised his arm and tling-a-ling settled himself contentedly upon his master's shoulder.

placing the empty cage on the counter. sin sin wa plunged his hand down into the bag and drew out the gleaming wooden joss. this he set beside the cage. with never a glance at the mummy figure of sam tuk, he walked around the counter, raven on shoulder, and grasping the end of the laden shelves, he pulled the last section smoothly to the left, showing that it was attached to a sliding door. the establishments of sin sin wa were as full of surprises as a sicilian trinketbox.

the double purpose of the timbering which had been added to this old storage vault was now revealed. it not only served to enlarge the store-room, but also shut off from view a second portion of the cellar, smaller than the first, and containing appointments which indicated that it was sometimes inhabited.

there was an oil-stove in the room, which, like that adjoining it, was evidently unprovided with any proper means of ventilation. a paper-shaded lamp hung from the low roof. the floor was covered with matting, and there were arm-chairs, a divan and other items of furniture, which had been removed from mrs. sin's sanctum in the dismantled house of a hundred raptures. in a recess a bed was placed, and as sin sin wa came in mrs. sin was standing by the bed looking down at a woman who lay there.

mrs. sin wore her kimona of embroidered green silk and made a striking picture in that sordid setting. her black hair she had dyed a fashionable shade of red. she glanced rapidly across her shoulder at sin sin wa—a glance of contempt with which was mingled faint distrust.

“so,” she said, in chinese, “you have come at last.” sin sin wa smiled. “they watched the old fox,” he replied. “but their eyes were as the eyes of the mole.”

still aside, contemptuously, the woman regarded him, and:

“suppose they are keener than you think?” she said. “are you sure you have not led them—here?”

“the snail may not pursue the hawk,” murmured sin sin wa; “nor the eye of the bat follow his flight.”

“smartest leg,” remarked the raven.

“yes, yes, my little friend,” crooned sin sin wa, “very soon now you shall see the paddy-fields of ho-nan and watch the great yellow river sweeping eastward to the sea.”

“pah!” said mrs. sin. “much—very much—you care about the paddy-fields of ho-nan, and little, oh, very little, about the dollars and the traffic! you have my papers?”

“all are complete. with those dollars for which i care not, a man might buy the world—if he had but enough of the dollars. you are well known in poplar as 'mrs. jacobs,' and your identity is easily established—as 'mrs. jacobs.' you join the mahratta at the albert dock. i have bought you a post as stewardess.”

mrs. sin tossed her head. “and juan?”

“what can they prove against your juan if you are missing?”

mrs. sin nodded towards the bed.

with slow and shuffling steps sin sin wa approached. he continued to smile, but his glittering eye held even less of mirth than usual. tucking his hands into his sleeves, he stood and looked down—at rita irvin.

her face had acquired a waxen quality, but some of her delicate coloring still lingered, lending her a ghastly and mask-like aspect. her nostrils and lips were blanched, however, and possessed a curiously pinched appearance. it was impossible to detect the fact that she breathed, and her long lashes lay motionless upon her cheeks.

sin sin wa studied her silently for some time, then:

“yes,” he murmured, “she is beautiful. but women are like adder's eggs. he is a fool who warms them in his bosom.” he turned his slow regard upon mrs. sin. “you have stained your hair to look even as hers. it was discreet, my wife. but one is beautiful and many-shadowed like a copper vase, and the other is like a winter sunset on the poppy-fields. you remind me of the angry red policeman, and i tremble.”

“tremble as much as you like,” said mrs. sin scornfully, “but do something, think; don't leave everything to me. she screamed tonight—and someone heard her. they are searching the river bank from door to door.”

“lo!” murmured sin sin wa, “even this i had learned, nor failed to heed the beating of a distant drum. and why did she scream?”

“i was—keeping her asleep; and the prick of the needle woke her.”

“tchee, tchee,” crooned sin sin wa, his voice sinking lower and lower and his eye nearly closing. “but still she lives—and is beautiful.”

“beautiful!” mocked mrs. sin. “a doll-woman, bloodless and nerveless!”

“so—so. yet she, so bloodless and nerveless, unmasked the secret of kazmah, and she, so bloodless and nerveless, struck down—”

mrs. sin ground her teeth together audibly.

“yes, yes!” she said in sibilant chinese. “she is a robber, a thief, a murderess.” she bent over the unconscious woman, her jewel-laden fingers crooked and menacing. “with my bare hands i would strangle her, but—”

“there must be no marks of violence when she is found in the river. tchee, chee—it is a pity.”

“number one p'lice chop, lo!” croaked the raven, following this remark with the police-whistle imitation.

mrs. sin turned and stared fiercely at the one-eyed bird.

“why do you bring that evil, croaking thing here?” she demanded. “have we not enough risks?”

sin sin wa smiled patiently.

“too many,” he murmured. “for failure is nothing but the taking of seven risks when six were enough. come—let us settle our affairs. the 'jacobs' account is closed, but it is only a question of hours or days before the police learn that the wharf as well as the house belongs to someone of that name. we have drawn our last dollar from the traffic, my wife. our stock we are resigned to lose. so let us settle our affairs.”

“smartest—smartest,” croaked tling-a-ling, and rattled ghostly castanets.