a city of the blind! six millions of people suddenly deprived of sight!

the disaster sounds impossible—a nightmare, the wild vapourings of a diseased imagination—and yet why not? given a favourable atmospheric condition, something colossal in the way of a fire, and there it is. and there, somewhere folded away in the book of nature, is the simple remedy.

such thoughts as these flashed through hackness's mind as he stood under the portico of the lyceum theatre, quite helpless and inert for the moment.

but the darkness was thicker and blacker than anything he had ever imagined. it was absolutely the darkness that could be felt. hackness could hear the faint scratching of matches all around him, but there was no glimmer of light anywhere. and the atmosphere was thick, stifling, greasy. yet it was not quite as stifling as perfervid imagination suggested. the very darkness suggested suffocation. still, there was air, a sultry light breeze that set the murk in motion, and mercifully brought from some purer area the oxygen that made life possible. there was always air, thank god, to the end of the four days' night.

nobody spoke for a time. not a sound of any kind could be heard. it was odd to think that a few miles away the country might be sleeping under the clear stars. it was terrible to think that hundreds of thousands of people must be standing lost in the streets and yet near to home.

a little way off a dog whined, a child in a sweet refined voice cried that she was lost. an anxious mother called in reply. the little one had been forgotten in the first flood of that awful darkness. by sheer good luck hackness was enabled to locate the child. he could feel that her wraps were rich and costly, though the same fatty slime was upon them. he caught the child up in his arms and yelled that he had got her. the mother was close by, yet full five minutes elapsed before hackness blundered upon her. something was whining and fawning about his feet.

he called upon grimfern, and the latter answered in his ear. cynthia was crying pitifully and helplessly. some women there were past that.

"for heaven's sake tell us what we are to do," grimfern gasped. "i flatter myself that i know london well, but i couldn't find my way home in this."

something was licking hackness's hand. it was the dog kim. there was just a chance here. he tore his handkerchief in strips and knotted it together. one end he fastened to the little dog's collar.

"it's kim," he explained. "tell the dog 'home.' there's just a chance that he may lead you home. we're very wonderful creatures, but one sensible dog is worth a million of us to-night. try it."

"and where are you going?" cynthia asked. she spoke high, for a babel of voices had broken out. "what will become of you?"

"oh, i am all right," hackness said with an affected cheerfulness. "you see, i was fairly sure that this would happen sooner or later. so i pigeon-holed a way of dealing with the difficulty. scotland yard listened, but thought me a bore all the same. this is the situation where i come in."

grimfern touched the dog and urged him forward.

kim gave a little bark and a whine. his muscular little body strained at the leash.

"it's all right," grimfern cried. "kim understands. that queer little pill-box of a brain of his is worth the finest intellect in england to-night."

cynthia whispered a faint good-night, and hackness was alone. as he stood there in the blackness the sense of suffocation was overwhelming. he essayed to smoke a cigarette, but he hadn't the remotest idea whether the thing was alight or not. it had no taste or flavour.

but it was idle to stand there. he must fight his way along to scotland yard to persuade the authorities to listen to his ideas. there was not the slightest danger of belated traffic, no sane man would have driven a horse in such dense night. hackness blundered along without the faintest idea to which point of the compass he was facing.

if he could only get his bearings he felt that he should be all right. he found his way into the strand at length; he fumbled up against someone and asked where he was. a hoarse voice responded that the owner fancied it was somewhere in piccadilly. there were scores of people in the streets standing about talking desperately, absolute strangers clinging to one another for sheer craving for company to keep the frayed senses together. the most fastidious clubman there would have chummed with the toughest hooligan rather than have his own thoughts for company.

hackness pushed his way along. if he got out of his bearings he adopted the simple experiment of knocking at the first door he came to and asking where he was. his reception was not invariably enthusiastic, but it was no time for nice distinctions. and a deadly fear bore everybody down.

at last he came to scotland yard, as the clocks proclaimed that it was half-past one. ghostly official voices told hackness the way to inspector williamson's office, stern officials grasped him by the arm and piloted him up flights of stairs. he blundered over a chair and sat down. out of the black cavern of space inspector williamson spoke.

"i am thankful you have come. you are just the man i most wanted to see. i want my memory refreshed over that scheme of yours," he said. "i didn't pay very much attention to it at the time."

"of course you didn't. did you ever know an original prophet who wasn't laughed at? still, i don't mind confessing that i hardly anticipated anything quite so awful as this. the very density of it makes some parts of my scheme impossible. we shall have to shut our teeth and endure it. nothing really practical can be done so long as this fog lasts."

"but, man alive, how long will it last?"

"perhaps an hour or perhaps a week. do you grasp what an awful calamity faces us?"

williamson had no reply. so long as the fog lasted, london was in a state of siege, and, not only this, but every house in it was a fort, each depending upon itself for supplies. no bread could be baked, no meal could be carried round, no milk or vegetables delivered so long as the fog remained. given a day or two of this and thousands of families would be on the verge of starvation. it was not a pretty picture that hackness drew, but williamson was bound to agree with every word of it.

these two men sat in the darkness till what should have been the dawn, whilst scores of subordinates were setting some sort of machinery in motion to preserve order.

hackness stumbled home to his rooms about nine o'clock in the morning, without having succeeded in persuading the officials to grant him permission to experiment. mechanically he felt for his watch to see the time. the watch was gone. hackness smiled grimly. the predatory classes had not been quite blind to the advantages of the situation.

there was no breakfast for hackness for the simple reason that it had been found impossible to light the kitchen fire. but there was a loaf of bread, some cheese, and a knife. hackness fumbled for his bottled beer and a glass. there were many worse breakfasts in london that morning.

he woke presently, conscious that a clock was striking nine. after some elaborate thought and the asking of a question or two from another inmate of the house, hackness found to his horror that he had slept the clock round nearly twice. it was nine o'clock in the morning, twenty-three hours since he had fallen asleep! and, so far as hackness could judge, there were no signs of the fog's abatement.

he changed his clothes and washed the greasy slime off him so far as cold water and soap would allow. there were plenty of people in the streets, hunting for food for the most part; there were tales of people found dead in the gutters. progression was slow, but the utter absence of traffic rendered it safe and possible. men spoke with bated breath, the weight of the great calamity upon them.

news that came from a few miles outside the radius spoke of clear skies and bright sunshine. there was a great deal of sickness, and the doctors had more than they could manage, especially with the young and the delicate.

and the calamity looked like getting worse. six million people were breathing what oxygen there was. hackness returned to his chambers to find eldred awaiting him.

"this can't go on, you know," the latter said tersely.

"of course it can't," hackness replied. "all the air is getting exhausted. come with me down to scotland yard and help to try and persuade williamson to test my experiment."

"what! do you mean to say he is still obstinate?"

"well, perhaps he feels different to-day. come along."

williamson was in a chastened frame of mind. he had no optimistic words when hackness suggested that nothing less than a violent meteorological disturbance would clear the deadly peril of the fog away. it was time for drastic remedies, and if they failed things would be no worse than before.

"but can you manage it?" williamson asked.

"i fancy so," hackness replied. "it's a risk, of course, but everything has been ready for a long time. we could start after to-morrow midnight, or any time for that matter."

"very well," williamson sighed with the air of a man who realises that after all the tooth must come out. "if this produces a calamity i shall be asked to send in my resignation. if i refuse——"

"if you refuse there is more than a chance that you won't want another situation," hackness said grimly. "let's get the thing going, eldred."

they crawled along through the black suffocating darkness, feeble, languid, and sweating at every pore. there was a murky closeness in the vitiated atmosphere that seemed to take all the strength and energy away. at any other time the walk to clarence terrace would have been a pleasure, now it was a penance. they found their objective after a deal of patience and trouble. hackness yelled in the doorway. there was a sound of footsteps and cynthia grimfern spoke.

"ah, what a relief it is to know that you are all right," she said. "i pictured all sorts of horrors happening to you. will this never end, martin?"

she cried softly in her distress. hackness felt for her hand and pressed it tenderly.

"we are going to try my great theory," he said. "eldred is with me, and we have got williamson's permission to operate with the aerophane. where is sir edgar?"

grimfern was in the big workshop in the garden. as best he could, he was fumbling over some machinery for the increase of power in electric lighting. hackness took a queer-looking lamp with double reflectors from his pocket.

"shut off that dynamo," he said, "and give me the flex. i've got a little idea here bramley, the electrician, lent me. with that 1000-volt generator of yours i can get a light equal to 40,000 candles. there."

flick went the switch, and the others staggered back with their hands to their eyes. the great volume of light, impossible to face under ordinary circumstances, illuminated the workshop with a faint glow like a winter's dawn. it was sufficient for all practical purpose, but to eyes that had seen absolutely nothing for two days and nights very painful.

the great volume of light, impossible to face under ordinary circumstances, illuminated the workshop with a faint glow.

cynthia laughed hysterically. she saw the men grimed and dirty, blackened and greasy, as if they were fresh from a stoker's hole in a tropical sea. they saw a tall, graceful girl in the droll parody of a kitchen-maid who had wiped a tearful face with a blacklead brush.

but they could see. along the whole floor of the workshop lay a queer, cigar-shaped instrument with grotesque wings and a tail like that of a fish, but capable of being turned in any direction. it seemed a problem to get this strange-looking monster out of the place, but as the whole of the end of the workshop was constructed to pull out, the difficulty was not great.

this was sir edgar grimfern's aerophane, built under his own eyes and with the assistance of hackness and eldred.

"it will be a bit of risk in the dark," sir edgar said thoughtfully.

"it will, sir, but i hope it will mean the saving of a great city," hackness remarked. "we shall have no difficulty in getting up, and as to the getting down, don't forget that the atmosphere a few miles beyond the outskirts of london is quite clear. if only the explosives are strong enough!"

"don't theorise," eldred snapped. "we've got a good day's work before we start. and there is no time to be lost."

"luncheon first," sir edgar suggested, "served in here. it will be plain and cold; but, thank goodness, there is plenty of it. my word, after that awful darkness what a blessed thing light is once more!"

two hours after midnight the doors of the workshop were pulled away and the aerophane was dragged on its carriage into the garden. the faint glimmer of light only served to make the blackness all the thicker. the three men waved their hands silently to cynthia and jumped in. a few seconds later and they were whirred and screwed away into the suffocating fog.