when kerry left bond street the mistiness of the night was developing into definite fog. it varied in different districts. thus, st. paul's churchyard had been clear of it at a time when it had lain impenetrably in trafalgar square. when, an hour and a half after setting out in the commandeered rolls-royce, kerry groped blindly along limehouse causeway, it was through a yellow murk that he made his way—a vapour which could not only be seen, smelled and felt, but tasted.

he was in one of his most violent humours. he found some slight solace in the reflection that the impudent chauffeur, from whom he had parted in west india dock road, must experience great difficulty in finding his way back to the west end.

“damn the fog!” he muttered, coughing irritably.

it had tricked him, this floating murk of london; for, while he had been enabled to keep the coupe in view right to the fringe of dockland, here, as if bred by old london's river, the fog had lain impenetrably.

chief inspector kerry was a man who took many risks, but because of this cursed fog he had no definite evidence that chada's car had gone to a certain house. right of search he had not, and so temporarily he was baffled.

now the nearest telephone was his objective, and presently, where a blue light dimly pierced the mist, he paused, pushed open a swing door, and stepped into a long, narrow passage. he descended three stairs, and entered a room laden with a sickly perfume compounded of stale beer and spirits; of greasy humanity—european, asiastic, and african; of cheap tobacco and cheaper scents; and, vaguely, of opium.

it was fairly well lighted, but the fog had penetrated here, veiling some of the harshness of its rough appointments. an unsavoury den was malay jack's, where flotsam of the river might be found. yellow men there were, and black men and brown men. but all the women present were white.

fan-tan was in progress at one of the tables, the four players being apparently the only strictly sober people in the room. a woman was laughing raucously as kerry entered, and many coarse-voiced conversations were in progress; but as he pulled the rough curtain walls aside and walked into the room, a hush, highly complimentary to the chief inspector's reputation, fell upon the assembly. only the woman's raucous laughter continued, rising, a hideous solo, above a sort of murmur, composed of the words “red kerry!” spoken in many tones.

kerry ignored the sensation which his entrance had created, and crossed the room to a small counter, behind which a dusky man was standing, coatless and shirt sleeves rolled up. he had the skin of a malay but the features of a stage irishman of the old school. and, indeed, had he known his own pedigree, which is a knowledge beyond the ken of any man, partly irish he might have found himself indeed to be.

this was malay jack, the proprietor of one of the roughest houses in limehouse. his expression, while propitiatory, was not friendly, but:

“don't get hot and bothered,” snapped kerry viciously. “i want to use your telephone, that's all.”

“oh,” said the other, unable to conceal his relief, “that's easy. come in.”

he raised a flap in the counter, and kerry, passing through, entered a little room behind the bar. here a telephone stood upon a dirty, littered table, and, taking it up:

“city four hundred,” called the chief inspector curtly. a moment later: “hallo! yes,” he said. “chief inspector kerry speaking. put me through to my department, please.”

he stood for a while waiting, receiver in hand, and smiled grimly to note that the uproar in the room beyond had been resumed. evidently malay jack had given the “all clear” signal. then:

“chief inspector kerry speaking,” he said again. “has detective sergeant durham reported?”

“yes,” was the reply, “half an hour ago. he's standing-by at limehouse station. he followed you in a taxi, but lost you on the way owing to the fog.”

“i don't wonder,” said kerry. “his loss is not so great as mine. anything else?”

“nothing else.”

“good. i'll speak to limehouse. good-bye.”

he replaced the receiver and paused for a moment, reflecting. extracting a piece of tasteless gum from between his teeth, he deposited it in the grate, where a sickly fire burned; then, tearing the wrapper from a fresh slip, he resumed his chewing and stood looking about him with unseeing eyes. fierce they were as ever, but introspective in expression.

famous for his swift decisions, for once in a way he found himself in doubt. malay jack had keen ears, and there were those in the place who had every reason to be interested in the movements of a member of the criminal investigation department, especially of one who had earned the right to be dreaded by the rats of limehouse. london's peculiar climate fought against him, but he determined to make no more telephone calls but to proceed to limehouse police station.

he stepped swiftly into the bar, and, as he had anticipated, nearly upset the proprietor, who was standing listening by the half-open door. kerry smiled fiercely into the ugly face, lifted the flap, and walked down the room, through the aisle between the scattered tables, where the air was heavy with strange perfumes, touched now with the bite of london fog, and where slanting eyes and straight eyes, sober eyes and drunken eyes, regarded him furtively. something of a second hush there was, but one not so complete as the first.

kerry pulled the curtain aside, mounted the stair, walked along the passage and out through the swing door into the yellow gloom of the causeway. ten slow steps he had taken when he detected a sound of pursuit. like a flash he turned, clenching his fists. then:

“inspector!” whispered a husky voice.

“yes! who are you? what do you want?”

a dim form loomed up through the fog.

“my name is peters, sir. inspector preston knows me.”

kerry had paused immediately under a street lamp, and now he looked into the pinched, lean face of the speaker, and:

“i've heard of you,” he snapped. “got some information for me?”

“i think so; but walk on.”

chief inspector kerry hesitated. peters belonged to a class which kerry despised with all the force of his straightforward character. a professional informer has his uses from the police point of view; and while evidence of this kind often figured in reports made to the chief inspector, he personally avoided contact with such persons, as he instinctively and daintily avoided contact with personal dirt. but now, something so big was at stake that his hesitation was only momentary.

a vision of the pale face of lady rourke, of the golden head leaning weakly back upon the cushions of the coupe, as he had glimpsed it in bond street, rose before his mind's eye as if conjured up out of the fog. peters shuffled along beside him, and:

“young chada's done himself in to-night,” continued the husky voice. “he brought a swell girl to the old man's house an hour ago. i was hanging about there, thinking i might get some information. i think she was doped.”

“why?” snapped kerry.

“well, i was standing over on the other side of the street. lou chada opened the door with a key; and when the light shone out i saw him carry her in.”

“carry her in?”

“yes. she was in evening dress, with a swell cloak.”

“the car?”

“he came out again and drove it around to the garage at the back.”

“why didn't you report this at once?”

“i was on my way to do it when i saw you coming out of malay jack's.”

the man's voice shook nervously, and:

“what are you scared about?” asked kerry savagely. “got anything else to tell me?”

“no, no,” muttered peters. “only i've got an idea he saw me.”

“who saw you?”

“lou chada.”

“what then?”

“well, only—don't leave me till we get to the station.”

kerry blew down his nose contemptuously, then stopped suddenly.

“stand still,” he ordered. “i want to listen.”

silent, they stood in a place of darkness, untouched by any lamplight. not a sound reached them through the curtain of fog. asiatic mystery wrapped them about, but kerry experienced only contempt for the cowardice of his companion, and:

“you need come no farther,” he said coldly. “good night.”

“but———” began the man.

“good night,” repeated kerry.

he walked on briskly, tapping the pavement with his malacca. the sneaking figure of the informer was swallowed up in the fog. but not a dozen paces had the chief inspector gone when he was arrested by a frenzied scream, rising, hollowly, in a dreadful, muffled crescendo. words reached him.

“my god, he's stabbed me!”

then came a sort of babbling, which died into a moan.

“hell!” muttered kerry, “the poor devil was right!”

he turned and began to run back, fumbling in his pocket for his electric torch. almost in the same moment that he found it he stumbled upon peters, who lay half in the road and half upon the sidewalk.

kerry pressed the button, and met the glance of upturned, glazing eyes. even as he dropped upon his knee beside the dying man, peters swept his arm around in a convulsive movement, having the fingers crooked, coughed horribly, and rolled upon his face.

switching off the light of the torch, kerry clenched his jaws in a tense effort of listening, literally holding his breath. but no sound reached him through the muffling fog. a moment he hesitated, well knowing his danger, then viciously snapping on the light again, he quested in the blood-stained mud all about the body of the murdered man.

“ah!”

it was an exclamation of triumph.

one corner hideously stained, for it had lain half under peters's shoulder, kerry gingerly lifted between finger and thumb a handkerchief of fine white silk, such as is carried in the breast pocket of an evening coat.

it bore an ornate monogram worked in gold, and representing the letters “l. c.” oddly enough, it was the corner that bore the monogram which was also bloodstained.