Out of his childhood there came a sudden, incongruous memory of an albino ferret he had once seen weaving its body ceaselessly across the wire netting of its cage. There was the same reptile grace in the monstrous shape, almost twice as high as a man, that reared itself in baffled fury against the grille. The metal bowed but did not yield beneath the pressure; then the bear dropped to the ground, grunted softly and padded away. It slashed once or twice at the fallen haversack, scattering a few tins of food into the snow, and vanished as silently as it had come.
A very shaken Professor Millward reached the University three hours later, after moving in short bounds from one refuge to the next. After all these years he was no longer alone in the city. He wondered if there were other visitors, and that same night he knew the answer. Just before dawn he heard, quite distinctly, the cry of a wolf from somewhere in the direction of Hyde Park.
By the end of the week he knew that the animals of the North were on the move. Once he saw a reindeer running southward, pursued by a pack of silent wolves, and sometimes in the night there were sounds of deadly conflict. He was amazed that so much life still existed in the white wilderness between London and the Pole. Now something was driving it southward, and the knowledge brought him a mounting excitement. He did not believe that these fierce survivors would flee from anything save Man.
The strain of waiting was beginning to affect Professor Millward's mind, and for hours he would sit in the cold sunlight, his furs wrapped around him, dreaming of rescue and thinking of the way in which men might be returning to England. Perhaps an expedition had come from North America across the Atlantic ice. It might have been years upon its way. But why had it come so far north? His favorite theory was that the Atlantic ice-packs were not safe enough for heavy traffic further to the south.
One thing, however, he could not explain to his satisfaction. There had been no air reconnaissance; it was hard to believe that the art of flight had been lost so soon.
Sometimes he would walk along the ranks of books, whispering now and then to a well-loved volume. There were books here that he had not dared to open for years, they reminded him so poignantly of the past. But now, as the days grew longer and brighter, he would sometimes take down a volume of poetry and re-read his old favorites. Then he would go to the tall windows and shout the magic words over the rooftops, as if they would break the spell that had gripped the world.
It was warmer now, as if the ghosts of lost summers had returned to haunt the land. For whole days the temperature rose above freezing, while in many places flowers were breaking through the snow. Whatever was approaching from the north was nearer, and several times a day that enigmatic roar would go thundering over the city, sending the snow sliding upon a thousand roofs.
There were strange, grinding undertones that Professor Millward found baffling and even ominous. At times it was almost as if he were listening to the clash of mighty armies, and sometimes a mad but dreadful thought came into his mind and would not be dismissed. Often he would wake in the night and imagine he heard the sound of mountains moving to the sea.
So the summer wore away, and as the sound of that distant battle drew steadily nearer Professor Millward was the prey of ever more violently alternating hopes and fears. Although he saw no more wolves or bears—they seemed to have fled southward—he did not risk leaving the safety of his fortress. Every morning he would climb to the highest window of the tower and search the northern horizon with field-glasses. But all he ever saw was the stubborn retreat of the snows above Hampstead, as they fought their bitter rearguard action against the sun.
His vigil ended with the last days of the brief summer. The grinding thunder in the night had been nearer than ever before, but there was still nothing to hint at its real distance from the city. Professor Millward felt no premonition as he climbed to the narrow window and raised his binoculars to the northern sky.
As a watcher from the walls of some threatened fortress might have seen the first sunlight glinting on the spears of an advancing army, so in that moment Professor Millward knew the truth. The air was crystal-clear, and the hills were sharp and brilliant against the cold blue of the sky. They had lost almost all their snow. Once he would have rejoiced at that, but it meant nothing now.
Overnight, the enemy he had forgotten had conquered the last defenses and was preparing for the final onslaught. As he saw that deadly glitter along the crest of the doomed hills, Professor Millward understood at last the sound he had heard advancing for so many months. It was little wonder he had dreamed of mountains on the march.
Out of the North, their ancient home, returning in triumph to the lands they had once possessed, the glaciers had come again.
TECHNICAL ERROR
It was one of those accidents for which no one could be blamed. Richard Nelson had been in and out of the generator pit a dozen times, taking temperature readings to make sure that the unearthly chill of liquid helium was not seeping through the insulation. This was the first generator in the world to use the principle of superconductivity. The windings of the immense stator had been immersed in a helium bath, and the miles of wire now had a resistance too small to be measured by any means known to man.
Nelson noted with satisfaction that the temperature had not fallen further than expected. The insulation was doing its work; it would be safe to lower the rotor into the pit. That thousand-ton cylinder was now hanging fifty feet above Nelson's head, like the business end of a mammoth drop hammer. He and everyone else in the power station would feel much happier when it had been lowered onto its bearings and keyed into the turbine shaft.
Nelson put away his notebook and started to walk toward the ladder. At the geometric center of the pit, he made his appointment with destiny.
The load on the power network had been steadily increasing for the last hour, while the zone of twilight swept across the continent. As the last rays of sunlight faded from the clouds, the miles of mercury arcs along the great highways sprang into life. By the million, fluorescent tubes began to glow in the cities; housewives switched on their radio-cookers to prepare the evening meal. The needles of the megawattmeters began to creep up the scales.
These were the normal loads. But on a mountain three hundred miles to the south a giant cosmic ray analyzer was being rushed into action to await the expected shower from the new supernova in Capricornus, which the astronomers had detected only an hour before. Soon the coils of its five-thousand-ton magnets began to drain their enormous currents from the thyratron converters.
A thousand miles to the west, fog was creeping toward the greatest airport in the hemisphere. No one worried much about fog, now, when every plane could land on its own radar in zero visibility, but it was nicer not to have it around. So the giant dispersers were thrown into operation, and nearly a thousand megawatts began to radiate into the night, coagulating the water droplets and clearing great swaths through the banks of mist.
The meters in the power station gave another jump, and the engineer on duty ordered the stand-by generators into action. He wished the big, new machine was finished; then there would be no more anxious hours like these. But he thought he could handle the load. Half an hour later the Meteorological Bureau put out a general frost warning over the radio. Within sixty seconds, more than a million electric fires were switched on in anticipation. The meters passed the danger mark and went on soaring.
With a tremendous crash three giant circuit breakers leaped from their contacts. Their arcs died under the fierce blast of the helium jets. Three circuits had opened— but the fourth breaker had failed to clear. Slowly, the great copper bars began to glow cherry-red. The acrid smell of burning insulation filled the air and molten metal dripped heavily to the floor below, solidifying at once on the concrete slabs. Suddenly the conductors sagged as the load ends broke away from their supports. Brilliant green arcs of burning copper flamed and died as the circuit was broken. The free ends of the enormous conductors fell perhaps ten feet before crashing in
to the equipment below. In a fraction of a second they had welded themselves across the lines that led to the new generator.
Forces greater than any yet produced by man were at war in the windings of the machine. There was no resistance to oppose the current, but the inductance of the tremendous windings delayed the moment of peak intensity. The current rose to a maximum in an immense surge that lasted several seconds. At that instant, Nelson reached the center of the pit.
Then the current tried to stabilize itself, oscillating wildly between narrower and narrower limits. But it never reached its steady state; somewhere, the overriding safety devices came into operation and the circuit that should never have been made was broken again. With a last dying spasm, almost as violent as the first, the current swiftly ebbed away. It was all over.
When the emergency lights came on again, Nelson's assistant walked to the lip of the rotor pit. He didn't know what had happened, but it must have been serious. Nelson, fifty feet down, must have been wondering what it was all about.
"Hello, Dick!" he shouted. "Have you finished? We'd better see what the trouble is."
There was no reply. He leaned over the edge of the great pit and peered into it. The light was very bad, and the shadow of the rotor made it difficult to see what was below. At first it seemed that the pit was empty, but that was ridiculous; he had seen Nelson enter it only a few minutes ago. He called again.
"Hello! You all right, Dick?"
Again no reply. Worried now, the assistant began to descend the ladder. He was halfway down when a curious noise, like a toy balloon bursting very far away, made him look over his shoulder. Then he saw Nelson, lying at the center of the pit on the temporary woodwork covering the turbine shaft. He was very still, and there seemed something altogether wrong about the angle at which he was lying.
Ralph Hughes, chief physicist, looked up from his littered desk as the door opened. Things were slowly returning to normal after the night's disasters. Fortunately, the trouble had not affected his department much, for the generator was unharmed. He was glad he was not the chief engineer: Murdock would still be snowed under with paperwork. The thought gave Dr. Hughes considerable satisfaction.
"Hello, Doc," he greeted the visitor. "What brings you here? How's your patient getting on?"
Doctor Sanderson nodded briefly. "He'll be out of hospital in a day or so. But I want to talk to you about him."
"I don't know the fellow—I never go near the plant, except when the Board goes down on its collective knees and asks me to. After all, Murdock's paid to run the place."
Sanderson smiled wryly. There was no love lost between the chief engineer and the brilliant young physicist. Their personalities were too different, and there was the inevitable rivalry between theoretical expert and "practical" man.
"I think this is up your street, Ralph. At any rate, it's beyond me. You've heard what happened to Nelson?"
"He was inside my new generator when the power was shot into it, wasn't he?"
"That's correct. His assistant found him suffering from shock when the power was cut off again."
"What kind of shock? It couldn't have been electric; the windings are insulated, of course. In any case, I gather that he was in the center of the pit when they found him."
"That's quite true. We don't know what happened. But he's now come round and seems none the worse—apart from one thing." The doctor hesitated a moment as if choosing his words carefully.
"Well, go on! Don't keep me in suspense!"
"I left Nelson as soon as I saw he would be quite safe, but about an hour later Matron called me up to say he wanted to speak to me urgently. When I got to the ward he was sitting up in bed looking at a newspaper with a very puzzled expression. I asked him what was the matter. He answered, 'Something's happened to me, Doc.' So I said, 'Of course it has, but you'll be out in a couple of days.' He shook his head; I could see there was a worried look in his eyes. He picked up the paper he had been looking at and pointed to it. 'I can't read any more,' he said.
"I diagnosed amnesia and thought: This is a nuisance! Wonder what else he's forgotten? Nelson must have read my expression, for he went on to say, 'Oh, I still know the letters and words—but they're the wrong way round! I think something must have happened to my eyes.' He held up the paper again. 'This looks exactly as if I'm seeing it in a mirror,' he said. 'I can spell out each word separately, a letter at a time. Would you get me a looking glass? I want to try something.'
"I did. He held the paper to the glass and looked at the reflection. Then he started to read aloud, at normal speed. But that's a trick anyone can learn—compositors have to do it with type—and I wasn't impressed. On the other hand, I couldn't see why an intelligent fellow like Nelson should put over an act like that. So I decided to humor him, thinking the shock must have given his mind a bit of a twist. I felt quite certain he was suffering from some delusion, though he seemed perfectly normal.
"After a moment he put the paper away and said, 'Well, Doc., what do you make of that?' I didn't know quite what to say without hurting his feelings, so I passed the buck and said, 'I think I'll have to hand you over to Dr. Humphries, the psychologist. It's rather outside my province.' Then he made some remark about Dr. Humphries and his intelligence tests, from which I gathered he had already suffered at his hands."
"That's correct," interjected Hughes. "All the men are grilled by the Psychology Department before they join the company. All the same, it's surprising what gets through," he added thoughtfully.
Dr. Sanderson smiled, and continued his story.
"I was getting up to leave when Nelson said, 'Oh, I almost forgot. I think I must have fallen on my right arm. The wrist feels badly sprained.' 'Let's look at it,' I said, bending to pick it up. 'No, the other arm,' Nelson said, and held up his left wrist. Still humoring him, I answered, 'Have it your own way. But you said your right one, didn't you?'
"Nelson looked puzzled. 'So what?' he replied. 'This is my right arm. My eyes may be queer, but there's no argument about that. There's my wedding ring to prove it. I've not been able to get the darned thing off for five years.'
"That shook me rather badly. Because you see, it was his left arm he was holding up, and his left hand that had the ring on it. I could see that what he said was quite true. The ring would have to be cut to get it off again. So I said, 'Have you any distinctive scars?' He answered, 'Not that I can remember.'
"'Any dental fillings?'"
" 'Yes, quite a few.' "
"We sat looking at each other in silence while a nurse went to fetch Nelson's records. 'Gazed at each other with a wild surmise' is just about how a novelist might put it. Before the nurse returned, I was seized with a bright idea. It was a fantastic notion, but the whole affair was becoming more and more outrageous. I asked Nelson if I could see the things he had been carrying in his pockets. Here they are."
Dr. Sanderson produced a handful of coins and a small, leather-bound diary. Hughes recognized the latter at once as an Electrical Engineer's Diary; he had one in his own pocket. He took it from the doctor's hand and flicked it open at random, with that slightly guilty feeling one always has when a stranger's—still more, a friend's—diary falls into one's hands.
And then, for Ralph Hughes, it seemed that the foundations of his world were giving way. Until now he had listened, to Dr. Sanderson with some detachment, wondering what all the fuss was about. But now the incontrovertible evidence lay in his own hands, demanding his attention and defying his logic.
For he could read not one word of Nelson's diary. Both the print and the handwriting were inverted, as if seen in a mirror.
Dr. Hughes got up from his chair and walked rapidly around the room several times. His visitor sat silently watching him. On the fourth circuit he stopped at the window and looked out across the lake, overshadowed by the immense white wall of the dam. It seemed to reassure him, and he turned to Dr. Sanderson again.
"You expect me to believe that Nelson has been lateral
ly inverted in some way, so that his right and left sides have been interchanged?"
"I don't expect you to believe anything. I'm merely giving you the evidence. If you can draw any other conclusion I'd be delighted to hear it. I might add that I've checked Nelson's teeth. All the fillings have been transposed. Explain that away if you can. Those coins are rather interesting, too."
Hughes picked them up. They included a shilling, one of the beautiful new, beryl-copper crowns, and a few pence and halfpence. He would have accepted them as change without hesitation. Being no more observant than the next man, he had never noticed which way the Queen's head looked. But the lettering—Hughes could picture the consternation at the Mint if these curious coins ever came to its notice. Like the diary, they too had been laterally inverted.
Dr. Sanderson's voice broke into his reverie.
"I've told Nelson not to say anything about this. I'm going to write a full report; it should cause a sensation when it's published. But we want to know how this has happened. As you are the designer of the new machine, I've come to you for advice."
Dr. Hughes did not seem to hear him. He was sitting at his desk with his hands outspread, little fingers touching. For the first time in his life he was thinking seriously about the difference between left and right.
Dr. Sanderson did not release Nelson from hospital for several days, during which he was studying his peculiar patient and collecting material for his report. As far as he could tell, Nelson was perfectly normal, apart from his inversion. He was learning to read again, and his progress was swift after the initial strangeness had worn off. He would probably never again use tools in the same way that he had done before the accident; for the rest of his life, the world would think him left-handed. However, that would not handicap him in any way.