A Treasury of Great Science Fiction Vol 2 Part 27

"Nonsense!" said Jim. "The alarms would have gone off. We've got duplicate circuits, operating independently."

"Er-the second alarm circuit isn't connected up yet," his a.s.sistant reminded him. That shook Jim; he left without a word, while we stood arguing and pa.s.sing the oxygen bottle around like a pipe of peace.

He came back ten minutes later with a sheepish expression. It was one of those accidents that couldn't possibly happen; we'd had one of our rare eclipses by Earth's shadow that night; part of the air purifier had frozen up, and the single alarm in the circuit had failed to go off. Half a million dollars' worth of chemical and electronic engineering had let us down completely. Without Claribel, we should soon have been slightly dead.

So now, if you visit any s.p.a.ce station, don't be surprised if you hear an inexplicable s.n.a.t.c.h of bird song.

There's no need to be alarmed: on the contrary, in fact, it will mean that you're being doubly safeguarded, at practically no extra expense.

TAKE A DEEP BREATH.

A LONG TIME AGO I discovered that people who've never left Earth have certain fixed ideas about conditions in s.p.a.ce. Everyone "knows," for example, that a man dies instantly and horribly when exposed to the vacuum that exists beyond the atmosphere. You'll find numerous gory descriptions of exploded s.p.a.ce travelers in the popular literature, and I won't spoil your appet.i.te by repeating them here. Many of those tales, indeed, are basically true. I've pulled men back through the air lock who were very poor advertis.e.m.e.nts for s.p.a.ce flight.

Yet, at the same time, there are exceptions to every rule-even this one. I should know, for I learned the hard way.

We were on the last stages of building Communications Satellite Two; all the main units had been joined together, the living quarters had been pressurized, and the station had been given the slow spin around its axis that had restored the unfamiliar sensation of weight. I say "slow," but at its rim our two-hundred-foot-diameter wheel was turning at thirty miles an hour. We had, of course, no sense of motion, but the centrifugal force caused by this spin gave us about half the weight we would have possessed on Earth. That was enough to stop things from drifting around, yet not enough to make us feel uncomfortably sluggish after our weeks with no weight at all.

Four of us were sleeping in the small cylindrical cabin known as Bunk-house Number 6 on the night that it happened. The bunkhouse was at the very rim of the station; if you imagine a bicycle wheel, with a string of sausages replacing the tire, you have a good idea of the layout. Bunkhouse Number 6 was one of these sausages, and we were slumbering peacefully inside it.I was awakened by a sudden jolt that was not violent enough to cause me alarm, but which did make me sit up and wonder what had happened. Anything unusual in a s.p.a.ce station demands instant attention, so I reached for the intercom switch by my bed. "h.e.l.lo, Central," I called. "What was that?"

There was no reply; the line was dead.

Now thoroughly alarmed, I jumped out of bed-and had an even bigger shock. There was no gravity. I shot up to the ceiling before I was able to grab a stanchion and bring myself to a halt, at the cost of a sprained wrist.

It was impossible for the entire station to have suddenly stopped rotating. There was only one answer; the failure of the intercom and, as I quickly discovered, of the lighting circuit as well forced us to face the appalling truth. We were no longer part of the station; our little cabin had somehow come adrift, and had been slung off into s.p.a.ce like a raindrop falling on a spinning flywheel.

There were no windows through which we could look out, but we were not in complete darkness, for the battery-powered emergency lights had come on. All the main air vents had closed automatically when the pressure dropped. For the time being, we could live in our own private atmosphere, even though it was not being renewed. Unfortunately, a steady whistling told us that the air we did have was escaping through a leak somewhere in the cabin.

There was no way of telling what had happened to the rest of the station. For all we knew, the whole structure might have come to pieces, and all our colleagues might be dead or in the same predicament as we-drifting through s.p.a.ce in leaking cans of air. Our one slim hope was the possibility that we were the only cast-aways, that the rest of the station was intact and had been able to send a rescue team to find us. After all, we were receding at no more than thirty miles an hour, and one of the rocket scooters could catch up to us in minutes.

It actually took an hour, though without the evidence of my watch I should never have believed that it was so short a time. We were now gasping for breath, and the gauge on our single emergency oxygen tank had dropped to one division above zero.

The banging on the wall seemed like a signal from another world. We banged back vigorously, and a moment later a m.u.f.fled voice called to us through the wall. Someone outside was lying with his s.p.a.ce-suit helmet pressed against the metal, and his shouted words were reaching us by direct conduction. Not as clear as radio-but it worked.

The oxygen gauge crept slowly down to zero while we had our council of war. We would be dead before we could be towed back to the station; yet the rescue ship was only a few feet away from us, with its air lock already open. Our little problem was to cross that few feet-without s.p.a.ce suits.

We made our plans carefully, rehearsing our actions in the full knowledge that there could be no repeat performance. Then we each took a deep, final swig of oxygen, flushing out our lungs. When we were all ready, I banged on the wall to give the signal to our friends waiting outside.

There was a series of short, staccato raps as the power tools got to work on the thin hull. We clung tightly to the stanchions, as far away as possible from the point of entry, knowing just what would happen. When it came, it was so sudden that the mind couldn't record the sequence of events. The cabin seemed to explode, and a great wind tugged at me. The last trace of air gushed from my lungs, through my already-opened mouth. And then- utter silence, and the stars shining through the gaping hole that led to life.

Believe me, I didn't stop to a.n.a.lyze my sensations. I think-though Ican never be sure that it wasn't imagination-that my eyes were smarting and there was a tingling feeling all over my body. And I felt very cold, perhaps because evaporation was already starting from my skin.

The only thing I can be certain of is that uncanny silence. It is never completely quiet in a s.p.a.ce station, for there is always the sound of machinery or air pumps. But this was the absolute silence of the empty void, where there is no trace of air to carry sound.

Almost at once we launched ourselves out through the shattered wall, into the full blast of the sun. I was instantly blinded-but that didn't matter, because the men waiting in s.p.a.ce suits grabbed me as soon as I emerged and hustled me into the air lock. And there, sound slowly returned as the air rushed in, and we remembered we could breathe again. The entire rescue, they told us later, had lasted just twenty seconds...

Well, we were the founding members of the Vacuum-Breathers' Club. Since then, at least a dozen other men have done the same thing, in similar emergencies. The record time in s.p.a.ce is now two minutes; after that, the blood begins to form bubbles as it boils at body temperature, and those bubbles soon get to the heart.

In my case, there was only one aftereffect. For maybe a quarter of a minute I had been exposed to real sunlight, not the feeble stuff that filters down through the atmosphere of Earth. Breathing s.p.a.ce didn't hurt me at all-but I got the worst dose of sunburn I've ever had in my life.

FREEDOM OF s.p.a.cE.

NOT MANY OF YOU, I suppose, can imagine the time before the satellite relays gave us our present world communications system. When I was a boy, it was impossible to send TV programs across the oceans, or even to establish reliable radio contact around the curve of the Earth without picking up a fine a.s.sortment of crackles and bangs on the way. Yet now we take interference-free circuits for granted, and think nothing of seeing our friends on the other side of the globe as clearly as if we were standing face to face. Indeed, it's a simple fact that without the satellite relays, the whole structure of world commerce and industry would collapse. Unless we were up here on the s.p.a.ce stations to bounce their messages around the globe, how do you think any of the world's big business organizations could keep their widely scattered electronic brains in touch with each other?

But all this was still in the future, back in the late seventies, when we were finishing work on the Relay Chain. I've already told you about some of our problems and near disasters; they were serious enough at the time, but in the end we overcame them all. The three stations s.p.a.ced around Earth were no longer piles of girders, air cylinders, and plastic pressure chambers. Their a.s.sembly had been completed, we had moved aboard, and could now work in comfort, unhampered by s.p.a.ce suits. And we had gravity again, now that the stations had been set slowly spinning. Not real gravity, of course; but centrifugal force feels exactly the same when you're out in s.p.a.ce. It was pleasant being able to pour drinks and to sit down without drifting away on the first air current.

Once the three stations had been built, there was still a year's solid work to be done installing all the radio and TV equipment that would lift the world's communications networks into s.p.a.ce. It was a great day when we established the first TV link between England and Australia. The signal was beamed up to us in Relay Two, as we sat above the center of Africa, we flashed it across to Three-poised over New Guinea-and they shot it down to Earth again, clear and clean after its ninety-thousand-mile journey.

These, however, were the engineers' private tests. The official opening of the system would be the biggest event in the history of world communication-an elaborate global telecast, in which every nation would take part. It would be a three-hour show, as for the first time the live TV camera roamed aroundthe world, proclaiming to mankind that the last barrier of distance was down.

The program planning, it was cynically believed, had taken as much effort as the building of the s.p.a.ce stations in the first place, and of all the problems the planners had to solve, the most difficult was that of choosing a compere or master of ceremonies to introduce the items in the elaborate global show that would be watched by half the human race.

Heaven knows how much conniving, blackmail, and downright character a.s.sa.s.sination went on behind the scenes. All we knew was that a week before the great day, a nonschedulcd rocket came up to orbit with Gregory Wendell aboard. This was quite a surprise, since Gregory wasn't as big a TV personality as, say, Jeffers Jackson in the U.S. or Vince Clifford in Britain. However, it seemed that the big boys had canceled each other out, and Gregg had got the coveted job through one of those compromises so well known to politicians.

Gregg had started his career as a disc jockey on a university radio station in the American Midwest, and had worked his way up through the Hollywood and Manhattan night-club circuits until he had a daily, nation-wide program of his own. Apart from his cynical yet relaxed personality, his biggest a.s.set was his deep velvet voice, for which he could probably thank his Negro blood. Even when you flatly disagreed with what he was saying-even, indeed, when he was tearing you to pieces in an interview-it was still a pleasure to listen to him.

We gave him the grand tour of the s.p.a.ce station, and even {strictly against regulations) took him out through the air lock in a s.p.a.ce .suit. He loved it all, but there were two things he liked in particular.

"Thfe.'air you make," he said, "it beats the stuff we have to breathe down in Ndw York. This is the first time my sinus trouble has gone since I went into TV." He also relished the low gravity; at the station's rim, a man had half his normal, Earth weight-and at the axis he had no weight at all.

However, the novelty of his surroundings didn't distract Gregg from his job. He spent hours at Communications Central, polishing his script and getting his cues right, and studying the dozens of monitor screens that would be his windows on the world. I came across him once while he was running through his introduction of Queen Elizabeth, who would be speaking from Buckingham Palace at the very end of the program. He was so intent on his rehearsal that he never even noticed I was standing beside him.

Well, that telecast is now part of history. For the first time a billion human beings watched a single program that came "live" from every corner of the Earth, and was a roll call of the world's greatest citizens. Hundreds of cameras on land and sea and air looked inquiringly at the turning globe; and at the end there was that wonderful shot of the Earth through a zoom lens on the s.p.a.ce station, making the whole planet recede until it was lost among the stars...

There were a few hitches, of course. One camera on the bed of the Atlantic wasn't ready on cue, and we had to spend some extra time looking at the Taj Mahal. And owing to a switching error Russian subt.i.tles were superimposed on the South American transmission, while half the U.S.S.R. found itself trying to read Spanish. But this was nothing to what might have happened.

Through the entire three hours, introducing the famous and the unknown with equal ease, came the mellow yet never orotund flow of Gregg's voice. He did a magnificent job; the congratulations came pouring up the beam the moment the broadcast finished. But he didn't hear them; he made one short, private call to his agent, and then went to bed.

Next morning, the Earth-bound ferry was waiting to take him back to any job he cared to accept. But it left without Gregg Wendell, now junior station announcer of Relay Two."They'll think I'm crazy," he said, beaming happily, "but why should I go back to that rat race down there? I've all the universe to look at, I can breathe smog-free air, the low gravity makes me feel a Hercules, and my three darling ex-wives can't get at me." He kissed his hand to the departing rocket.

"So long, Earth," he called. "I'll be back when I start pining for Broadway traffic jams and bleary penthouse dawns. And if I get homesick, I can look at anywhere on the planet just by turning a switch.

Why, I'm more in the middle of things here than I could ever be on Earth, yet I can cut myself off from the human race whenever I want to."

He was still smiling as he watched the ferry begin the long fall back to Earth, toward the fame and fortune that could have been his. And then, whistling cheerfully, he left the observation lounge in eight-foot strides to read the weather forecast for Lower Patagonia.

Pa.s.sER-BY.

IT'S ONLY FAIR TO WARN YOU, right at the start, that this is a story with no ending. But it has a definite beginning, for it was while we were both students at Astrotech that I met Julie. She was in her final year of solar physics when I was graduating, and during our last year at college we saw a good deal of each other. I've still got the woolen tam-o'shanter she knitted so that I wouldn't b.u.mp my head against my s.p.a.ce helmet. (No, I never had the nerve to wear it.) Unfortunately, when I was a.s.signed to Satellite Two, Julie went to the Solar Observatory-at the same distance from Earth, but a couple of degrees eastward along the orbit. So there we were, sitting twenty-two thousand miles above the middle of Africa-but with nine hundred miles of empty, hostile s.p.a.ce between us.

At first we were both so busy that the pang of separation was somewhat lessened. But when the novelty of life in s.p.a.ce had worn off, our thoughts began to bridge the gulf that divided us. And not only our thoughts, for I'd made friends with the communications people, and we used to have little chats over the interstation TV circuit. In some ways it made matters worse seeing each other face to face and never knowing just how many other people were looking in at the same time. There's not much privacy in a s.p.a.ce station...

Sometimes I'd focus one of our telescopes onto the distant, brilliant star of the observatory. In the crystal clarity of s.p.a.ce, I could use enormous magnifications, and could see every detail of our neighbors'

equipment- the solar telescopes, the pressurized spheres of the living quarters that housed the staff, the slim pencils of visiting ferry rockets that had climbed up from Earth. Very often there would be s.p.a.ce-suited figures moving among the maze of apparatus, and I would strain my eyes in a hopeless attempt at identification. It's hard enough to recognize anyone in a s.p.a.ce suit when you're only a few feet apart-but that didn't stop me from trying.

We'd resigned ourselves to waiting, with what patience we could muster, until our Earth leave was due in six months' time, when we had an unexpected stroke of luck. Less than half our tour of duty had pa.s.sed when the head of the transport section suddenly announced that he was going outside with a b.u.t.terfly net to catch meteors. He didn't become violent, but had to be shipped hastily back to Earth. I took over his job on a temporary basis and now had-in theory at least-the freedom of s.p.a.ce.

There were ten of the little low-powered rocket scooters under my proud command, as well as four of the larger interstation shuttles used to ferry stores and personnel from orbit to orbit. I couldn't hope to borrow one of those, but after several weeks of careful organizing I was able to carry out the plan I'd conceived some two micro-seconds after being told I was now head of transport.

There's no need to tell how I juggled duty lists, cooked logs and fuel registers, and persuaded mycolleagues to cover up for me. All that matters is that, about once a week, I would climb into my personal s.p.a.ce suit, strap myself to the spidery framework of a Mark III Scooter, and drift away from the station at minimum power. When I was well clear, I'd go over to full throttle, and the tiny rocket motor would hustle me across the nine-hundred-mile gap to the observatory.

The trip took about thirty minutes, and the navigational requirements were elementary. I could see where I was going and where I'd come from, yet I don't mind admitting that I often felt-well, a trifle lonely-around the mid-point of the journey. There was no other solid matter within almost five hundred miles-and it looked an awfully long way down to Earth. It was a great help, at such moments, to tune the suit radio to the general service band, and to listen to all the back-chat between ships and stations.

At mid-flight I'd have to spin the scooter around and start braking, and ten minutes later the observatory would be close enough for its details to be visible to the unaided eye. Very shortly after that I'd drift up to a small, plastic pressure bubble that was in the process of being fitted out as a spectroscopic laboratory-and there would be Julie, waiting on the other side of the air lock...

I won't pretend that we confined our discussions to the latest results in astrophysics, or the progress of the satellite construction schedule. Few things, indeed, were further from our thoughts; and the journey home always seemed to flash by at a quite astonishing speed.

It was around mid-orbit on one of those homeward trips that the radar started to flash on my little control panel. There was something large at extreme range, and it was coming in fast. A meteor, I told myself-maybe even a small asteroid. Anything giving such a signal should be visible to the eye: I read off the bearings and searched the star fields in the indicated direction. The thought of a collision never even crossed my mind; s.p.a.ce is so inconceivably vast that I was thousands of times safer than a man crossing a busy street on Earth.

There it was-a bright and steadily growing star near the foot of Orion. It already outshone Rigel, and seconds later it was not merely a star, but had begun to show a visible disk. Now it was moving as fast as I could turn my head; it grew to a tiny, misshaped moon, then dwindled and shrank with that same silent, inexorable speed.

I suppose I had a clear view of it for perhaps half a second, and that half-second has haunted me all my life. The-object-had already vanished by the time I thought of checking the radar again, so I had no way of gauging how close it came, and hence how large it really was. It could have been a small object a hundred feet away-or a very large one, ten miles off. There is no sense of perspective in s.p.a.ce, and unless you know what you are looking at, you cannot judge its distance.

Of course, it could have been a very large and oddly shaped meteor; I can never be sure that my eyes, straining to grasp the details of so swiftly moving an object, were not hopelessly deceived. I may have imagined that I saw that broken, crumpled prow, and the cl.u.s.ter of dark ports like the sightless sockets of a skull. Of one thing only was I certain, even in that brief and fragmentary vision. If it was a ship, it was not one of ours. Its shape was utterly alien, and it was very, very old.

It may be that the greatest discovery of all time slipped from my grasp as I struggled with my thoughts midway between the two s.p.a.ce stations. But I had no measurements of speed or direction; whatever it was that I had glimpsed was now lost beyond recapture in the wastes of the solar system.

What should I have done? No one would ever have believed me, for I would have had no proof. Had I made a report, there would have been endless trouble. I should have become the laughingstock of the s.p.a.ce Service, would have been reprimanded for misuse of equipment-and would certainly not havebeen able to see Julie again. And to me, at that age, nothing else was as important. If you've been in love yourself, you'll understand; if not, then no explanation is any use.

So I said nothing. To some other man (how many centuries hence?) will go the fame for proving that we were not the first-born of the children of the sun. Whatever it may be that is circling out there on its eternal orbit can wait, as it has waited ages already.

Yet I sometimes wonder. Would I have made a report, after all-had I known that Julie was going to marry someone else?

THE CALL OF THE STARS.

DOWN THERE ON EARTH the twentieth century is dying. As I look across at the shadowed globe blocking the stars, I can see the lights of a hundred sleepless cities, and there are moments when I wish that I could be among the crowds now surging and singing in the streets of London, Capetown, Rome, Paris, Berlin, Madrid... Yes, I can see them all at a single glance, burning like fireflies against the darkened planet. The line of midnight is now bisecting Europe: in the eastern Mediterranean a tiny, brilliant star is pulsing as some exuberant pleasure ship waves her searchlights to the sky. I think she is deliberately aiming at us; for the past few minutes the flashes have been quite regular and startlingly bright.

Presently I'll call the communications center and find out who she is, so that I can radio back our own greetings.

Pa.s.sing into history now, receding forever down the stream of time, is the most incredible hundred years the world has ever seen. It opened with the conquest of the air, saw at its mid-point the unlocking of the atom-and now ends with the bridging of s.p.a.ce.

(For the past five minutes I've been wondering what's happening to Nairobi; now I realize that they are putting on a mammoth fireworks dis-play. Chemically fueled rockets may be obsolete out here-but they're still using lots of them down on Earth tonight.) The end of a century-and the end of a millennium. What will the hundred years that begin with two and zero bring? The planets, of course; floating there in s.p.a.ce, only a mile away, are the ships of the first Martian expedition. For two years I have watched them grow, a.s.sembled piece by piece, as the s.p.a.ce station itself was built by the men I worked with a generation ago.

Those ten ships are ready now, with all their crews aboard, waiting for the final instrument check and the signal for departure. Before the first day of the new century has pa.s.sed its noon, they will be tearing free from the reins of Earth, to head out toward the strange world that may one day be man's second home.

As I look at the brave little fleet that is now preparing to challenge infinity, my mind goes back forty years, to the days when the first satellites were launched and the moon still seemed very far away. And I remember- indeed, I have never forgotten-my father's fight to keep me down on Earth.

There were not many weapons he had failed to use. Ridicule had been the first: "Of course they can do it," he had sneered, "but what's the point? Who wants to go out into s.p.a.ce while there's so much to be done here on Earth? There's not a single planet in the solar system where men can live. The moon's a burnt-out slag heap, and everywhere else is even worse. This is where we were meant to live."

Even then (I must have been eighteen or so at the time) I could tangle him up in points of logic. I can remember answering, "How do you know where we were meant to live, Dad? After all, we were in the sea for about a billion years before we decided to tackle the land. Now we're making the next big jump: I don't know where it will lead-nor did that first fish when it crawled up on the beach, and started to sniff the air."So when he couldn't outargue me, he had tried subtler pressures. He was always talking about the dangers of s.p.a.ce travel, and the short working life of anyone foolish enough to get involved in rocketry.

At that time, people were still scared of meteors and cosmic rays; like the "Here Be Dragons" of the old map makers, they were the mythical monsters on the still-blank celestial charts. But they didn't worry me; if anything, they added the spice of danger to my dreams.

While I was going through college, Father was comparatively quiet. My training would be valuable whatever profession I took up in later life, so he could not complain-though he occasionally grumbled about the money I wasted buying all the books and magazines on astronautics that I could find. My college record was good, which naturally pleased him; perhaps he did not realize that it would also help me to get my way.

All through my final year I had avoided talking of my plans. I had even given the impression (though I am sorry for that now) that I had abandoned my dream of going into s.p.a.ce. Without saying anything to him, I put in my application to Astrotech, and was accepted as soon as I had graduated.

The storm broke when that long blue envelope with the embossed head-ing "Inst.i.tute of Astronautical Technology" dropped into the mailbox. I was accused of deceit and ingrat.i.tude, and I do not think I ever forgave my father for destroying the pleasure I should have felt at being chosen for the most exclusive-and most glamorous-apprenticeship the world has ever known.

The vacations were an ordeal; had it not been for Mother's sake, I do not think I would have gone home more than once a year, and I always left again as quickly as I could. I had hoped that Father would mellow as my training progressed and as he accepted the inevitable, but he never did.

Then had come that stiff and awkward parting at the s.p.a.ceport, with the rain streaming down from leaden skies and beating against the smooth walls of the ship that seemed so eagerly waiting to climb into the eternal sunlight beyond the reach of storms. I know now what it cost my father to watch the machine he hated swallow up his only son: for I understand many things today that were hidden from me then.

He knew, even as we parted at the ship, that he would never see me again. Yet his old, stubborn pride kept him from saying the only words that might have held me back. I knew that he was ill, but how ill, he had told no one. That was the only weapon he had not used against me, and I respect him for it.

Would I have stayed had I known? It is even more futile to speculate about the unchangeable past than the unforeseeable future; all I can say now is that I am glad I never had to make the choice. At the end he let me go; he gave up his fight against my ambition, and a little while later his fight with Death.

So I said good-by to Earth, and to the father who loved me but knew no way to say it. He lies down there on the planet I can cover with my hand; how strange it is to think that of the countless billion human beings whose blood runs in my veins, I was the very first to leave his native world...

The new day is breaking over Asia; a hairline of fire is r.i.m.m.i.n.g the eastern edge of Earth. Soon it will grow into a burning crescent as the sun comes up out of the Pacific-yet Europe is preparing for sleep, except for those revelers who will stay up to greet the dawn.

And now, over there by the flagship, the ferry rocket is coming back for the last visitors from the station.

Here comes the message I have been waiting for: CAPTAIN STEVENS PRESENTS HIS COMPLIMENTS TO THE STATION COMMANDER. BLAST-OFF WILL BE IN NINETY.

MINUTES; HE WILL BE GLAD TO SEE YOU ABOARD NOW.

Well, Father, now I know how you felt: time has gone full circle. Yet I hope that I have learned from the mistakes we both made, long ago. I shall remember you when I go over there to the flagship Starfire andsay good-by to the grandson you never knew.

THE MAN WHO SOLD THE MOON

by Robert A. Heinlein

CHAPTER ONE.

"YOU'VE GOT TO BE A BELIEVER!".

George Strong snorted at his partner's declaration. "Delos, why don't you give up? You've been singing this tune for years. Maybe someday men will get to the Moon, though I doubt it. In any case, you and I will never live to see it. The loss of the power satellite washes the matter up for our generation."

D. D. Harriman grunted. "We won't see it if we sit on our fat behinds and don't do anything to make it happen. But we can make it happen."

"Question number one: how? Question number two: why?"

" 'Why?' The man asks 'why.' George, isn't there anything in your soul but discounts, and dividends?

Didn't you ever sit with a girl on a soft summer night and stare up at the Moon and wonder what was there?"

"Yeah, I did once. I caught a cold."