london was fog-bound. the threat of the past week had been no empty one. towards the hour of each wintry sunset had come the yellow racks, hastening dusk and driving folks more speedily homeward to their firesides. the dull reports of fog-signals had become a part of the metropolitan bombilation, but hitherto the choking mist had not secured a strangle-hold.

now, however, it had triumphed, casting its thick net over the city as if eager to stifle the pulsing life of the new babylon. in the neighborhood of the docks its density was extraordinary, and the purlieus of limehouse became mere mysterious gullies of smoke impossible to navigate unless one were very familiar with their intricacies and dangers.

chief inspector kerry, wearing a cardigan under his oilskins, tapped the pavement with the point of his malacca like a blind man. no glimmer of light could he perceive. he could not even see his companion.

“hell!” he snapped irritably, as his foot touched a brick wall, “where the devil are you, constable?”

“here beside you, sir,” answered p.c. bryce, of k division, his guide.

“which side?”

“here, sir.”

the constable grasped kerry's arm.

“but we've walked slap into a damn brick wall!”

“keep the wall on your left, sir, and it's all clear ahead.”

“clear be damned!” said kerry. “are we nearly there?”

“about a dozen paces and we shall see the lamp—if it's been lighted.”

“and if not we shall stroll into the river, i suppose?”

“no danger of that. even if the lamp's out, we shall strike the iron pillar.”

“i don't doubt it,” said kerry grimly.

they proceeded at a slow pace. dull reports and a vague clangor were audible. these sounds were so deadened by the clammy mist that they might have proceeded from some gnome's workshop deep in the bowels of the earth. the blows of a pile-driver at work on the surrey shore suggested to kerry's mind the phantom crew of hendrick hudson at their game of ninepins in the katskill mountains. suddenly:

“is that you, bryce?” he asked.

“i'm here, sir,” replied the voice of the constable from beside him.

“h'm, then there's someone else about.” he raised his voice. “hi, there! have you lost your way?”

kerry stood still, listening. but no one answered to his call.

“i'll swear there was someone just behind us, bryce!”

“there was, sir. i saw someone, too. a chinese resident, probably. here we are!”

a sound of banging became audible, and on advancing another two paces, kerry found himself beside bryce before a low closed door.

“hello! hello!” croaked a dim voice. “number one p'lice chop, lo! sin sin wa!”

the flat note of a police whistle followed.

“sin sin is at home,” declared bryce. “that's the raven.”

“does he take the thing about with him, then?”

“i don't think so. but he puts it in a cupboard when he goes out, and it never talks unless it can see a light.”

bolts were unfastened and the door was opened. out through the moving curtain of fog shone the red glow from a stove. a grotesque silhouette appeared outlined upon the dim redness.

“you wantchee me?” crooned sin sin wa.

“i do!” rapped kerry. “i've called to look for opium.”

he stepped past the chinaman into the dimly lighted room. as he did so, the cause of an apparent deformity which had characterized the outline of sin sin wa became apparent. from his left shoulder the raven partly arose, moving his big wings, and:

“smartest leg!” it shrieked in kerry's ear and rattled imaginary castanets.

the chief inspector started, involuntarily.

“damn the thing!” he muttered. “come in, bryce, and shut the door. what's this?”

on a tea-chest set beside the glowing stove, the little door of which was open, stood a highly polished squat wooden image, gilded and colored red and green. it was that of a leering chinaman, possibly designed to represent buddha, and its jade eyes seemed to blink knowingly in the dancing rays from the stove.

“sin sin wa's joss,” murmured the proprietor, as bryce closed the outer door. “me shinee him up; makee joss glad. number one piecee joss.”

kerry turned and stared into the pock-marked smiling face. seen in that dim light it was not unlike the carved face of the image, save that the latter possessed two open eyes and the chinaman but one. the details of the room were indiscernible, lost in yellowish shadow, but the eye of the raven and the eye of sin sin wa glittered like strange jewels.

“h'm,” said kerry. “sorry to interrupt your devotions. light us.”

“allee velly proper,” crooned sin sin wa.

he took up the joss tenderly and bore it across the room. opening a little cupboard set low down near the floor he discovered a lighted lantern. this he took out and set upon the dirty table. then he placed the image on a shelf in the cupboard and turned smilingly to his visitors.

“number one p'lice!” shrieked the raven.

“here!” snapped kerry. “put that damn thing to bed!”

“velly good,” murmured sin sin wa complacently.

he raised his hand to his shoulder and the raven stepped sedately from shoulder to wrist. sin sin wa stooped.

“come, tling-a-ling,” he said softly. “you catchee sleepee.”

the raven stepped down from his wrist and walked into the cupboard.

“so fashion, lo!” said sin sin wa, closing the door.

he seated himself upon a tea-chest beside the useful cupboard, resting his hands upon his knees and smiling.

kerry, chewing steadily, had watched the proceedings in silence, but now:

“constable bryce,” he said crisply, “you recognize this man as sin sin wa, the occupier of the house?”

“yes, sir,” replied bryce.

he was not wholly at ease, and persistently avoided the chinaman's oblique, beady eye.

“in the ordinary course of your duty you frequently pass along this street?”

“it's the limit of the limehouse beat, sir. poplar patrols on the other side.”

“so that at this point, or hereabout, you would sometimes meet the constable on the next beat?”

“well, sir,” bryce hesitated, clearing his throat, “this street isn't properly in his district.”

“i didn't say it was!” snapped kerry, glaring fiercely at the embarrassed constable. “i said you would sometimes meet him here.”

“yes, sometimes.”

“sometimes. right. did you ever come in here?”

the constable ventured a swift glance at the savage red face, and:

“yes, sir, now and then,” he confessed. “just for a warm on a cold night, maybe.”

“allee velly welcome,” murmured sin sin wa.

kerry never for a moment removed his fixed gaze from the face of bryce.

“now, my lad,” he said, “i'm going to ask you another question. i'm not saying a word about the warm on a cold night. we're all human. but—did you ever see or hear or smell anything suspicious in this house?”

“never,” affirmed the constable earnestly.

“did anything ever take place that suggested to your mind that sin sin wa might be concealing something—upstairs, for instance?”

“never a thing, sir. there's never been a complaint about him.”

“allee velly proper,” crooned sin sin wa.

kerry stared intently for some moments at bryce; then, turning suddenly to sin sin wa:

“i want to see your wife,” he said. “fetch her.”

sin sin wa gently patted his knees.

“she velly bad woman,” he declared. “she no hate topside pidgin.”

“don't talk!” shouted kerry. “fetch her!”

sin sin wa turned his hands palms upward.

“me no hate gotchee wifee,” he murmured.

kerry took one pace forward.

“fetch her,” he said; “or—” he drew a pair of handcuffs from the pocket of his oilskin.

“velly bad luck,” murmured sin sin wa. “catchee trouble for wifee no got.”

he extended his wrists, meeting the angry glare of the chief inspector with a smile of resignation. kerry bit savagely at his chewing-gum, glancing aside at bryce.

“did you ever see his wife?” he snapped.

“no, sir. i didn't know he had one.”

“no habgotchee,” murmured sin sin wa, “velly bad woman.”

“for the last time,” said kerry, stooping and thrusting his face forward so that his nose was only some six inches from that of sin sin wa, “where's mrs. sin?”

“catchee lun off,” replied the chinaman blandly. “velly bad woman. tlief woman. catchee stealee alla my dollars!”

“eh!”

kerry stood upright, moving his shoulders and rattling the handcuffs.

“comee here when sin sin wa hate gone for catchee shavee, liftee alla my dollars, and-pff! chee-lo!”

he raised his hand and blew imaginary fluff into space. kerry stared down at him with an expression in which animal ferocity and helplessness were oddly blended. then:

“bryce,” he said, “stay here. i'm going to search the house.”

“very good, sir.”

kerry turned again to the chinaman.

“is there anyone upstairs?” he demanded.

“nobody hate. sin sin wa alla samee lonesome. catchee shinum him joss.”

kerry dropped the handcuffs back into the pocket of his overall and took out an electric torch. with never another glance at sin sin wa he went out into the passage and began to mount the stairs, presently finding himself in a room filled with all sorts of unsavory rubbish and containing a large cupboard. he uttered an exclamation of triumph.

crossing the littered floor, and picking his way amid broken cane chairs, tea-chests, discarded garments and bedlaths, he threw open the cupboard door. before him hung a row of ragged clothes and a number of bowler hats. directing the ray of the torch upon the unsavory collection, he snatched coats and hats from the hooks upon which they depended and hurled them impatiently upon the floor.

when the cupboard was empty he stepped into it and began to bang upon the back. the savagery of his expression grew more marked than usual, and as he chewed his maxillary muscles protruded extraordinarily.

“if ever i sounded a brick wall,” he muttered, “i'm doing it now.”

tap where he would—and he tapped with his knuckles and with the bone ferrule of his cane—there was nothing in the resulting sound to suggest that that part of the wall behind the cupboard was less solid than any other part.

he examined the room rapidly, then passed into another one adjoining it, which was evidently used as a bedroom. the latter faced towards the court and did not come in contact with the wall of the neighboring house. in both rooms the windows were fastened, and judging from the state of the fasteners were never opened. in that containing the cupboard outside shutters were also closed. despite this sealing-up of the apartments, traces of fog hung in the air. kerry descended the stairs.

snapping off the light of his torch, he stood, feet wide apart, staring at sin sin wa. the latter, smiling imperturbably, yellow hands resting upon knees, sat quite still on the tea-chest. constable bryce was seated on a corner of the table, looking curiously awkward in his tweed overcoat and bowler hat, which garments quite failed to disguise the policeman. he stood up as kerry entered. then:

“there used to be a door between this house and the next,” said kerry succinctly. “my information is exact and given by someone who has often used that door.”

“bloody liar,” murmured sin sin wa.

“what!” shouted kerry. “what did you say, you yellow-faced mongrel!”

he clenched his fists and strode towards the chinaman.

“sarcee feller catchee pullee leg,” explained the unmoved sin sin wa. “velly bad man tellee lie for makee bhoberry—getchee poor chinaman in tlouble.”

in the fog-bound silence kerry could very distinctly be heard chewing. he turned suddenly to bryce.

“go back and fetch two men,” he directed. “i should never find my way.”

“very good, sir.”

bryce stepped to the door, unable to hide the relief which he experienced, and opened it. the fog was so dense that it looked like a yellow curtain hung in the opening.

“phew!” said bryce. “i may be some little time, sir.”

“quite likely. but don't stop to pick daisies.”

the constable went out, closing the door. kerry laid his cane on the table, then stooped and tossed a cud of chewing-gum into the stove. from his waistcoat pocket he drew out a fresh piece and placed it between his teeth. drawing a tea-chest closer to the stove, he seated himself and stared intently into the glowing heart of the fire.

sin sin wa extended his arm and opened the little cupboard.

“number one p'lice,” croaked the raven drowsily.

“you catchee sleepee, tling-a-ling,” said sin sin wa.

he took out the green-eyed joss, set it tenderly upon a corner of the table, and closed the cupboard door. with a piece of chamois leather, which he sometimes dipped into a little square tin, he began to polish the hideous figure.