TWO

After a week, the vessel returned to its usual Earth orbit. The manned satellites reported it was englobed for an hour in a rainbow ripple of luminance. That meant the Sigman would receive visitors: almost the sole signal which men believed they had unambiguously decoded. Because those welcomes never lasted more than a few days, spacecraft and personnel were kept on standby, according to schemes which had formerly been the subject of fierce scholarly and political wrangling. Nowadays assignments were made on a somewhat more rational basis.

Not that that said anything very noble about Homo sapiens, Yvonne Canter reflected. (Meanwhile she scrambled into a coverall, grabbed the bag she always kept packed, closed her apartment, took the elevator fifty floors down to the conurb's garage, set the pilot of her car for Armstrong Base, lit a cigarette, and tried to relax. She did not succeed.) Three years of frustration had drained most of the prestige, professional or international, out of being personally on the scene. Besides, everything that happened was fully recorded in every feasible way and put on the open data lines. You could mull it over in the comfort and privacy of your office and have as good a chance of getting a publishable paper as did the poor devils who'd sweated to gather such a maddeningly tiny and vague increment of information.

That's what they think, Yvonne told herself. Doubtless they've been right hitherto. But this time, oh, this time, maybe— The blood beat high within her.

The Denver streets were only thinly in use at five a.m.

Traffic Control's computers steered the car out of town In short order. When their electronic writ no longer ran, the pilot opened fuel cells to maximum, till the electrics whined aloud, and made the 300-odd-kilometre run inside qi ninety minutes. Yvonne hardly noticed the flat agricultural landscape reel by, nor the sprawling complex through which she finally rolled.

The observation did cross a mind otherwise churning with plans: Not alone Armstrong, the working spaceport, had lost glamour. The same had happened to Kennedy's R & D—to all of man's astronautical facilities. With a star-ship overhead, you continued ferrying supplies to the Lunar and Martian stations, you continued organizing a Jupiter expedition, you spoke of sending men to Saturn; but your heart wasn't in it.

She came back to alertness when she sat before Colonel Almeida's desk for briefing. Lift-off was set at 9.45; she'd arrive first by two hours— 'I forget. Who else is coming?'

'Just Wang,' he told her. 'The Europeans haven't finished repairs after the Copernicus crash, you know.

We offered to carry Duclos or whoever for them, but they declined. I suspect they've about decided to save their money and use second-hand material. The Russians—um —they informed Centre that Serov is ill and no substitute immediately available, therefore they'll sit this dance out. My guess is they're hurting more from their last fiscal crisis than they care to admit.'

'Wang and me? Well… at least we'll be less crowded,'

Almeida studied her. She was a tall woman, slender, verging on thinness, though ordinarily her careful dressing and grooming brought a number of excellent features to notice. Her face was likewise rather.long and thin: high cheekbones, curved nose, pointed chin, a structure attractive in its way and brought alive by the full mouth, the lustrous dark eyes under arching brows, a complexion to which no one of her age, thirty, had a legal right. The coverall and the normally shoulder-length black hair drawn into a severe bun did her less than justice.

'I didn't realize Wang annoyed you,' the intelligence officer said slowly.

She laughed. 'On camera the whole time, who makes a pass at whom? Besides, he's robotically correct.'

Seriously, a touch hesitantly: 'No, nothing to complain about. I shouldn't have spoken. He's simply not cheerful company. Under that stiff surface he's too tense, or should I say intense? You feel he never stops watching you, calculating what you'll do next. It gets on the nerves.'

Almeida refrained from answering that she had given him an exaggerated description of his impression of her own personality. Her standoffishness, her half-fanatical concentration on work at hand, made him wonder if she had anyone you might call a close friend— Parents and other kin back east, Berdt, Jewish name, didn't that suggest she had a warm place to fly back to? Or had Professor and Mrs Berdt taken overmuch pride in their brilliant-girl, unwittingly driving her from them by urging her without pause towards achievement?… Almeida doubted Yvonne had had any bed partner in her life except her husband, and that marriage disintegrated within five years… two years ago, right?… She'd joined the Sigman project shortly before.

He recalled his attention to her: 'No worries, Andy. I'll be too busy to notice, this time.'

'What? You have a lead?'

'Maybe. A thought that came to me after the last session. I've been working with it since, and a pattern does finally seem to be emerging.' Enthusiasm made her suddenly beautiful. But she closed her lips and shook her head. 'I'd prefer to say no more until I've tried the idea out.'

Almeida tugged his military Vandyke beard. 'You've noted it, haven't you, in case of, um, accidents?'

'Certainly. In my study at home, with the rest of my papers.' Yvonne rose. 'If we're finished here, I'd like a bite to eat.'

She couldn't imagine she would ever weary of the sight as her pilot manoeuvred towards rendezvous.

In the left window, ten degrees wide at 75,000 kilometres' remove, Earth glowed against the dark.

Dayside was a hundred rich shades of blue, swirled over by dazzling pure whitenesses that were weather.

The blurred greenish brown glimpses of land were unidentifiable by her, as if she had already left for shores never trodden. Nightside was black, overlaid with faint shimmers, dancing with brief sparks that might be thunderstorms or might be cities.

Turning her glance away and letting pupils expand after that lambence, she found stars. Because of cabin illumination, they were actually no more than you might see from Pike's Peak, but unwinking and wintry-sharp. Athwart them floated the ship they had sent.

What you saw there was likewise fragmentary. The craft was—perhaps—more an interplay of enigmatic huge force-fields than it was metal, crystal, and synthetic. You saw two spheroids, shining coppery in colour. The larger, some hundred metres across, was entirely enclosed. From the hull protruded turrets, needles, discs, frames, domes, webs, less nameable objects, at whose functions you could merely guess.

They made no ugly chaos. Instead, the shapes and masses had a flowing, breathtaking unity, never static because the eye kept finding new angles, the mind new aspects; Parthenon, Chartres Cathedral, Taj Mahal, Taliesin West could not match this intricate simplicity, this serene dynamism.

About two kilometres aft, locked in place by hydromag-netics (?), a smaller, less spectacularly equipped globe was of skeletal construction, open to the void. Telescopes revealed a pattern which Yvonne couldn't help thinking had charm, playfulness. Yet around it could burn the energies that shape suns.

Astronomers had picked out the monstrous blaze of the ship, as it decelerated towards the Solar System, a light-year away. For a year and three-quarters that running star had waxed, while perplexity and anxiety on Earth bred panic often exploding into riot. Yvonne remembered anew how the calm words of Sigurd-sen's famous television lecture had turned her own tension to hope, yes, exuberance.

'—beyond doubt a spaceship from another planetary system. R. W. Bussard suggested back in the last century the principle it must be using. Interstellar space is not a total vacuum. In this galactic neighbourhood, the gas amounts to about one hydrogen atom per cubic centimetre. Little indeed!

However, when you travel at speeds comparable to light's—light speed, the never-quite-reachable maximum which the laws of relativity physics permit—• when you travel that fast, those few atoms, colliding with your ship, will release X-rays and charged particles in such lethal concentration that no material shielding can protect you from nearly instant death.

'No material shielding. But we have learned something ourselves about electromagnetic and nuclear forces. The reactor which probably supplies the electricity for your home uses those forces to contain a plasma of hydrogen atoms which move so violently that they fuse to make helium and thus generate power. Bussard theorized that similar forces, on a vast scale, might someday deflect interstellar gas at a safe distance from a starship. He went on to propose that, since the gas was under control, it could be channelled aft, could be made to undergo reactions and thereby power the ship. In other words, a Bussard vessel would "live off the country". Needing only a modest amount of fuel to get up to ramjet velocity, it could thereafter approach indefinitely close to the ultimate speed. So we could reach the nearer stars, not in millennia but in a mere few years. The gates of the universe would swing wide for humanity.

'Well, we've been anticipated by a more advanced civilization. That body has to be a Buzzard-type vessel. No reasonable alternative explanation has been suggested, among the hundreds that have been made. It is a spacecraft, coming in at about one-third gravity negative acceleration, which hints that the crew hails from a smaller planet than Earth. The chances are it comes from a nearby system, quite likely to investigate the curious. radio emissions its builders have been detecting from us for the past century. If so, judging by its present course, the most plausible origin is Sigma Draconis. This is a star not unlike Sol, a little more than eighteen light-years distant. We shall see.

'We shall have nothing to fear. On the contrary, we have a cosmos to gain. I know a few of my colleagues worry about the ship's photon drive. Apparently it does not expel matter for thrust. It does still another thing we have not learned how to do it. It uses an enormous gas laser to project radiation, a beam of photons, the most efficient kind of reaction motor we can imagine. If a beam of that intensity struck any part of Earth, the devastation would be beyond our imagining.

'This will not happen. I agree with those who hold that star-exploring civilizations must be peaceful, because otherwise they would have destroyed themselves before reaching the required level of technology. We ourselves, primitive though we are, have been forced—slowly, reluctantly, but forced by stark necessity—to create a measure of international stability, international arms control. I do not believe we will fall back into the nightmare condition of nuclear rockets ready to fire. I believe our children and grandchildren will go beyond today's uneasy, often surly limited co-operation, towards positive benignity.

'However, we don't need faith to reassure us about our visitors. They may not be saints, but they cannot be idiots. The least of interstellar distances is an immensity we can denumerate but can never conceive.

That is no fleet approaching us, it is a solitary ship—by all indications, smaller than many of ours.

Nonetheless it represents an achievement and an investment to beggar the Pyramids, the Great Wall, and the exploration of the Solar System. What can its crew gain by harming us? What loot can be worth a fraction of the freight charges, what population pressures can be relieved an iota, what ego gratification lies in attacking the defenseless after one has conquered the chasm?

'No, those travellers can only have a single prime desire —knowledge. Adventure and glory too, perhaps, but surely knowledge. And there, I trust, we are not hopelessly outclassed. We have information about entire worlds, planet-ography, biology, history, anthropology, everything we are and have been, to trade for what they can reveal to us.

'In fact, to be honest, what puzzles me is why the ship has come at all. It would be enormously easier and cheaper to exchange information by laser beams or the like. Obviously the builders of the vessel could have punched a signal here which would attract our notice.

'Are they too impatient for knowledge? It would take many lifetimes to establish a satisfactory mutual language, when thirty-six years must pass between question asked and answer received. A preliminary in-the-flesh expedition could lay the groundwork far more quickly. Thereafter we could indeed use interstellar television. Maybe the Sigma Draconians, if that is their home, have just this one craft, their ambassador to star after star.

'That's merely a guess, of course. I can't wait to learn the truth! Meanwhile, be assured our visitors will take due precautions. They will shut off their dangerous photon engine at the fringes of the Solar System and come in on a suitable drive—probably, I think, a superior version of our ion jet. And they will come in the same peace as the angels came to Bethlehem.

'Children of man, make ready for your guests.'

He was right about the alien's harmlessness. But everything else—.' And I've since wondered about the harmlessness. What has the cruel, cruel disappointment done to out poor, already sick and divided race? Eagerness returned. Will 1, I, here and now, really find the beginning of the way to lift it?

'Steady… Roll three degrees— Twelve gauss, wow, let's pull off a ways___Raise thrust six newtons___Bearing ten, zero, two and a half; range eight-point-four----Cut.'

Silence, free falling, stars in the windows.

The pilot yawned and stretched. 'Okay, Dr Canter, here's your stop,' he said prosaically. 'Want to rest awhile?'

'No, thank you.' She shivered. 'At once.' A second later she remembered to add, 'Please.'

The co-pilot nodded. 'I'll take you.' He unbuckled together with her. Already spacesuited, they made their final checks, secured jetpacks on shoulders, closed helmets, and cycled out the airlock.

Yvonne wished briefly she could cross alone to the ship, amidst the now undimmed splendour of the stars. But no. While her training after she joined the project was intensive, it had not equipped her to meet an emergency in raw space. Linked by a cord to the man's ankles, she hung on to her box of food and other supplies and let him tow her. He went slowly, cautiously, constantly taking sights with his dromometer, to keep them in the tunnel that the Sig-man had, for a time, opened in the forces around the vessel. Nevertheless, the humans brushed these more than once. It felt like pulling through a swift current of hot water. Deeper in, at full intensity, an invader would doubtless have been torn apart.

At the shivering translucent curtain of… different

energies… which covered a portal that had dilated in the hull, they stopped. The co-pilot unsnapped the lifeline from her suit, his free hand keeping a grip on her. Earthlight, reflected off his helmet, made him faceless, and a seething of static distorted his radio voice, as they hung for a moment there between stars and argosy. 'Okay?' he asked.

'Yes.'

'We'll—don't forget, we'll trail you in orbit. When you're ready to leave, when he dismisses you and flashes the signal, we'll haul around to the present configuration. Wait here for me to come and escort you back.'

'I'm not as new to these assignments as you seem to be!' she rapped. Recognizing her discourtesy, she made herself add, 'No offence meant. Excuse me. I want to get right to work. An extra minute could be precious.'

'Sure.' He released her. She tapped a control and jetted forward, through the curtain that let her pass but not the ship's air, inboard to confront the Sigman.