"According to Cass, it's not. The whole thing goes- mass, matter, gravitational and magnetic fields, everything. We verified that on the small tests of asteroids and planets. I see no reason to think she's wrong this time."

"So why isn't there total chaos around the star?""Cheshire Cat effect. Cass doesn't call it that-she uses a string of Science gibberish. But there's a time lag before the field stresses disappear from our universe. It's long enough to keep the star intact as it moves into the caesura. If there were colonies on the planets around the star-there aren't, of course, they were moved long ago-and if the caesura hadn't swallowed them, the colonies would see the star vanish but measure its residual gravitational field. That fades smoothly away over an eight-hour period."

"Suppose the caesura moves slowly, and takes more than eight hours?"

"Then the part of the star that hasn't been absorbed will collapse. If half of it is left behind, you'll get an explosion with as much energy as a supernova. The nice thing is that this can be done with any type of star, and you can do it when you choose. And by picking the right caesura geometry you can beam the emitted energy in a particular direction. You can keep the beam collimated, so it doesn't spread much over interstellar distances. Intergalactic, either, if you take extra care. And there's your weapon."

A weapon, indeed. The ultimate weapon. Drake stared at the doomed star, reduced now to a mere sliver of brilliance.

Only a thin sector of the right-hand side remained. Then he turned to look outward, toward the galactic edge. The stars blazed there, undiminished, but they were silent. Uncommunicating, controlled by the Shiva.

He knew now the power that lay within his hands. His own idea had been to use the caesuras to create a no-man's-land, an empty zone on the edge of Shiva territory. Even if the Shiva could cross that firebreak, the time it took would tell humans something more about the manner and speed of Shiva movement.

Now Mel was pointing out that they could do much more.

Pick a target star in the Silent Zone. Choose any planetless and expendable star in this region, or any other convenient place in the Galaxy. Create a caesura of the right dimensions and geometry.

Now if you moved the caesura to engulf your chosen ' star at the right speed, a tongue of energy from the stellar collapse would be thrown out into space. It would travel at a substantial fraction of the speed of light. When it reached the target star, any planets orbiting that star would become burned and lifeless cinders. The star's outer layers on one side would be stripped off. There was a chance that the star itself would explode.

There were more than enough available stars in the human sector of the Galaxy for a one-on-one matching with stars in the Silent Zone. The Shiva, whatever they were, could be destroyed.

Whatever they were. That was the trouble. It was easy to examine the pattern by which the Shiva had entered and spread through the Galaxy from outside, and conclude from the long silence of the old human colonies that the Shiva were ruthless destroyers, inimical to anything other than their own kind.

And hence to propose the old human solution, stated by Rome but surely far older: Shiva delenda est; "the Shiva must be destroyed."

Conclusion was not the same as proof. Suppose that the colonies throughout the Silent Zone still survived? Suppose there was some other reason for their failure to speak? The existence of the Shiva and the silence of the colonies were not the elements of a syllogism. They did not add up to a proof that the colonies no longer existed.

Drake wondered just what it would take to persuade him of that. Was he proving that the composites were wrong, when they called him back to consciousness? Maybe he was like them, lacking the resolve to do what had to be done.

He looked again at the sky, which now showed nothing at all where star and caesura had been. He turned to Mel Bradley.

"What happens to the caesura when it has done its work?"

"It just sits there, a permanent feature of space-time with zero associated mass-energy. It will never decay or go away.

Don't worry, though. I asked Cass Leemu the same question. Unless it's activated in the right way it won't absorb anything else. There's no danger that the caesuras will keep going and swallow up the universe."

"That wasn't what I was thinking. I was wondering if a caesura could go on and eat up another star."

"Any number. So far as we can tell there's no limit to how much matter or energy you can put into a caesura and kick right out of the universe. But rather than move one caesura all over the place, it's easier to make another one. Cass and I have the technique down cold.

We can make one for each star in the Galaxy-if you want us to."There was an implied suggestion behind Mel's words. Which means we could make one for each star in the Silent Zone, if you wanted us to, and have plenty of the Galaxy left afterward.

It was a solution, but one that Drake could not use. Not yet. Someday, maybe, when he had exhausted every other hope, or when absolute proof was produced to show that the Shiva were the destroyers that they seemed to be. But for the moment . . .

"Stay here. Make as many of the caesuras as you need for the firebreak. As soon as all the colonies are relocated to a safe region, remove the stars and get the break in position."

"Very good." Mel sounded disappointed. "And how should I use the caesuras, fast or slow?"

"Fast enough to avoid the problem of stellar collapse."

"If you say so. And the Silent Zone?"

"Stays silent, and untouched." Drake looked one last time toward the outer edge of the Galaxy, knowing that colonies were disappearing from the human community as he watched. He felt Mel Bradley's disapproval, weighted by the thoughts of hundreds of trillions of other composites across space.

"I intend to do something else about the Silent Zone," Drake continued. "You can start the return transmission any time. As soon as I'm back at headquarters I'm going to try a new approach."

It was one of the rare occasions when the thought of his own dissolution was preferable to the idea of what he had to do next. Dying once was not so bad. Everybody did it eventually, and it was part of your personal future even if you didn't know how or when.

Dying a billion times was less appealing.

The location of every lost world was well known. Drake had chosen one of the most recently silenced, vanished from the human community since the time of his own involvement.

He and Tom Lambert were on board a probe ship, downloaded to an inorganic form that shared the ship's eyes, ears, and communications unit.

Tom had taken charge of the ship's drive. "According to the records for other similar places," he said, "we're approaching the danger zone. That's the planet ahead."

They stared in silence at the image of a peaceful world. It was a look-alike for another planet about three hundred light-years away: same K-type primary; mass, size, orbital parameters and axial tilt within a few percent; atmosphere modified very slightly, if at all, to an Earth analog. Both worlds had been colonized by a human association of organic and inorganic forms within two million years of each other. Here were sister planets, celestial twins with one difference: this world, Argentil, after billions of years of active presence in the human community, had dropped all contact and refused to respond to any signals.

Tom finally broke the silence. "Do you want to hold our distance?"

"Everything we see is being sent back to headquarters?"

"Everything."

"Let's hold our position for one full Argentil day, and make sure we've seen everything that's down there. Then we'll go closer."

Drake suspected they had already seen all they were going to. Whatever the Shiva had done to this planet, they had not destroyed it or made it uninhabitable for humans. Changes had taken place in Argentil, particularly an increase in atmospheric carbon dioxide and water vapor, but those could be the result of natural long-term climatic changes. They could just as well be the work of humans. Either way, the planet was still comfortably habitable.

They were hovering far off on the sunward side. As the world turned slowly beneath the ship, Drake suddenly imagined himself with Ana, restored to human body form, strolling unsuited and bareheaded among the dark-green forest lands of Argentil.

The thought came as a shock. Ana had been absent from his mind for a long time. Once he would have sworn that could not happen, that no hour could pass in which he did not think about her."All right, Tom." Drake had to act. His mind felt oddly unbalanced. Maybe he had watched Argentil for too long.

"Let's go. Take us closer. Take us all the way down to a landing."

How could he not be thinking constantly about Ana, when she was the whole reason that he was wandering here on the outer rim of the Galaxy?

He heard Tom screaming, but his own mind was far away. He was not seeing Argentil as the ship closed in for its final approach pattern. When the fusion fires rose from the surface to vaporize the descending ship, he saw only Ana. She was standing before him, telling him not to worry: they would still enjoy the future together, when all these events were nothing but a remote blip on the distant horizon of time.

The ship's communications unit was not controlled by Drake's wandering consciousness. A brief final message, triggered by the attack, went as an S-wave signal back to headquarters: it said that this ship, like so many others, was being destroyed-by a system sent to Argentil to defend the planet from the Shiva.

One more attempt. After how many?

Drake had lost count.

He studied the screens. It was information of a sort, even though it only confirmed what he already knew.

Where a giant artificial colony had once floated in free space, the sensors now showed nothing at all. However, the outer layers of the nearest star, only four light-minutes away, revealed subtle changes in its spectrum. There were more metal absorption lines than had been shown in the old records. And a nearby planet, which had once supported a human colony, was silent but apparently untouched.

It seemed as though the Shiva destroyed free-space colonies, while leaving the planets that they conquered able to support life. Drake pondered that fact as his lead ship turned cautiously toward the planet. Instead of Tom Lambert accompanying him, Drake had been downloaded to both ships. His two electronic versions had decided on a strategy on the way out from headquarters. Ship combinations had been sent out before, without success. After a million failed attempts he no longer hoped for definitive answers. He would settle for some small additional scrap of information.

When the first ship was within a few light-seconds of the planet, the second one released a tiny pod. It lacked a propulsion system, but it contained miniature sensors, an uploaded copy of Drake, and a low-data-rate transmitter.

The pod hung silent and motionless in space, while Drake on board it watched the approach of the two main ships to the planet. The first one vanished in a haze of high-energy particles and radiation. The second turned to flee, but a rolling torus of fire arrowed to it from the place where the other ship had been destroyed.

Drake reached a conclusion: the transmission link was an Achilles' heel. The second ship should have been at a safe distance, but after the Shiva had killed the first ship they had been able to follow the tiny pulses of communication between the two.

It was another crumb of information about the Shiva. It told him that he had to be ultracautious in his own transmission. He began to send data out, warily and slowly, varying the strength and direction of the signal.

Thousands of receiving stations, all over the Galaxy, would each receive a disconnected nugget of information. When he was finished, headquarters would face the task of time-ordering the sequence of weak signals, allowing for travel times, and collating everything to a single message.

Drake sent the pulses out a thousand times, varying the order of the signal destinations. By the time that he was finished, twelve thousand years had passed and he had drifted far from the star where the ships had died.

He had no propulsion system. Even now, he dared not risk a rescue signal.

They also serve who only stand and wait.

He waited. For another one hundred and forty thousand interminable years, he waited. The pod contained minimal computing facilities and no other distractions. There was nothing for him to do.

At last he gave the internal command to turn off all systems within the pod.

"All systems?" The pod's intelligence was limited, but sufficient to follow the implications of the command.

"That is my instruction.""I am sorry, but I am unable to perform that command."

"I see. Very well. Give me override."

"That is permitted."

Final authority for pod operations was turned over to Drake.

He switched off all systems; was erased; became nothing.

Chapter 22.

"Her lips were red, her looks were free, Her locks were yellow as gold; Her skin was white as leprosy, The nightmare Life-in-Death was she, Who thicks man's blood with cold."

It wasn't working. Drake decided that a smarter man than he would have realized the truth long ago. With all their efforts, they had learned very little.

The most tangible piece of information had been provided by Mel Bradley: the rate of spread of the Shiva zone of influence was between one-half and three kilometers a second. In other words, the Shiva domain expanded across one light-year of space in between one hundred thousand and six hundred thousand Earth years. That had its own implications. The firebreak that Mel had made with the help of the caesuras was forty light-years thick. It had taken four million years before a world was lost on the "safe" side of it; twenty-five million years later, every world along the whole great arc of the firebreak was gone.

The other thing, pointed out by Cass Leemu, was more peculiar: the Shiva apparently spread faster through regions where humans had colonies. Logic said it ought to be the other way round, that the resistance of a colony ought to slow the Shiva. Instead, it speeded them up. A policy of flight, leaving a world before the Shiva were predicted to arrive, had proved the best defense for other colonies.

And that was it; the sum total of what they had learned, in fifty million years of effort and millions of star systems lost.

The good news, if that was the word for it, was that it would take a few billion more years before the entire galaxy became part of the Silent Zone.

Drake wondered what to suggest next to the composites. That humanity, in all its forms, should flee to another galaxy?

Universal flight didn't seem feasible, even if it was psychologically acceptable.

He turned his total attention to a single question: Was there anything, anything at all, that they had not tried? He could think of just one thing. They had sent specially trained colonies to worlds that in the next centuries or millennia were candidates to fall to the Shiva. It had been done with single organic entities, with inorganics, and with composites, and always with the same results: the colonies reported that everything was all right, that they were doing fine, no problems. Then one day they fell silent.

But here was the oddity: distant worlds were not affected. The Shiva influence was a local effect. If there was a way to be close enough to observe a world as it was lost, yet somehow far enough away that the observer would not be swallowed up in silence, then humanity might learn something new.

That prompted another thought: Could it be that they were not going early enough to the endangered worlds?

Suppose there were long-term changes, subtle warnings of the coming of the Shiva, that Drake's observers did notcatch because they had not lived long enough on the planet.

What sort of indicators were plausible? He couldn't say. Ice ages, variation in length of seasons, movement of polar caps, polarity reversal of magnetic fields, earthquakes, modified physiology of individuals at the cell level, homeostatic shift-it could be any or all of them. Despite all his studies, he was not, and would never be, a scientist.

But he could think of a way to test his idea. Embody someone in a long-lived form. Make thousands of copies of him, organic or inorganic. Send a copy to each world, long before the Shiva were expected there. Ask each one to wait, observe, and prepare. Tell him to be patient. Tell him to report back any anomaly, no matter how small.

Drake reached one more conclusion. He had been thinking "him," and it was not hard to see why. How could he ask anyone else to endure an interminable wait, especially one likely to end with final extinction?

It was not some indefinite "him." It was Drake.

It could be Drake and only Drake. He had to be the one. He would prepare, and he would send copies of himself. He would also be at headquarters and monitor every incoming message. And one day, before the whole galaxy was silenced, perhaps the Drake-that-goes and the Drake-that-stays would learn something useful.

And one other thing must be done. A certain crucial piece of information must be withheld from any copy of Drake who descended to each planet.

He would consult Cass to find out just how to do that.

Drake splayed his feet on the marshy surface and stared up for a last sight of the spacecraft. It was difficult, not only because the ship was dwindling in apparent size, but because as it rose higher the rate of motion across the sky decreased. Drake was embodied in a native form known as a mander. Its eyes were like a frog's eyes, good at seeing rapidly moving objects, less effective on anything that stayed in one position.

One final glimpse, and then the ship was gone. Human vision might follow it still, but Drake could not. It did not matter. He knew where it was and where it would remain, far beyond the atmosphere in a polar observation orbit.

He looked around. This planet, Lukoris, was his new home. He had better get used to it, because he was going to be here for a long time. Half a million years did not sound like much-if you said it fast. From three to five hundred thousand years were likely to elapse before the Shiva arrived. Half a million years of waiting, before this world became part of the expanding Silent Zone.

The first thing was to understand and feel at home in his own body. He had been animated less than ten minutes ago, as the ship was preparing to leave. Drake examined the mander's physiology with a fair amount of curiosity. He was supposed to live like this, awake or dormant, for a thousand human lifetimes. According to the composites this body would never age or wear out. Even if he were to remain continuously conscious, which was not his plan, the mander would be as healthy and limber in a million years as it was that day.

How could that be? But perhaps a better question was, why not? Why did organisms age at all?

The answer had been discovered, long, long ago, and soon followed by the longevity protocols. Death by aging was a far-off anachronism. But none of that explained, in a way that Drake could understand, why a being aged, or how current science could hold off old age indefinitely.

It was like much of science: important, useful, and totally mysterious.

Drake returned to the inspection of his body. This was, according to alien specialist Milton, the closest form to human on the whole planet. It was hard to believe.

Drake examined the mander's feet. They were large and webbed. The legs above them were long and powerfully muscled, ideal for long balanced leaps. If it swims like a frog, and jumps like a frog, and sees like a frog . . .

He stuck out one of his two tongues. It was short and not sticky or club ended. He had already known that, intellectually, but he wanted reassurance.