Behind him, all the noise suddenly stopped.

I braced myself for the blow.

And fainted.

He was lying across my legs, with the branch still in his hand. Jill and Ron were pulling at my shoulders. A pair of golden moons floated overhead.

I wriggled loose. I felt my head. It seemed intact.

Ron said, "The copseyes zapped him before he got to you."

"What about the others? Did they kill them?"

"I don't know." Ron ran his hands through his hair. "I was wrong. -Anarchy isn't stable. It comes apart too easily."

"Well, don't do any more experiments. Okay?"

People were beginning to stand up. They streamed toward the exits, gathering momentum, beneath the yellow gaze of the copseyes.

I heard footsteps. They jarred the earth.

I opened my eyes and saw the rammer.

He was six feet tall and ma.s.sively built. He wore a scarf and a pair of blue balloon pants, not too far out of style, but they didn't match. What they exposed of his skin was loose on him, as it he had shrunkwithin it. Indeed, he looked like a giraffe wearing an elephant's skin.

'Pa.s.serby," 1971 1971 .

From PROTECTOR .

Nick felt panic close around his throat. "You. You're Brennan?"

"Yah. And you're Nick Sohl. I saw you once in Confinement. But I don't recognize your friend.~'

"Lucas Garner." Luke had himself under control. "Your photographs don't do you justice, Brennan."

"I did something stupid," said the Brennan-monster. Its voice was no more human, its appearance no less intimidating. "I went to meet the Outsider. You were trying to do the same, weren't you?"

"Yes." There was a sardonic amus.e.m.e.nt in Luke's eyes and Luke's voice. Whether or not he believed the Brennan-monster, he was enjoying the situation. "Was there really an Outsider, Brennan?"

"Unless you want to quibble about definitions."

Sohl broke in. "For G.o.d's sake, Brennan! What happened happened to you?" to you?"

"That's a long story. Are we pressed for time? Of course not, you'd have started the motor. All right, I'd like to tell this my own way, so please maintain a respectful silence, remembering that if I hadn't gotten in the way you'd look just like this, and serve you right, too." He looked hard at the two men. "I'm wrong. You wouldn't. You're both past the age.

"Well, bear with me. There exists a race of bipeds that live near the edge of the globe of close-packed suns at the core of the galaxy.

"The most important thing about them is that they live in three stages of maturity. There is childhood, which is self-explanatory. There is the breeder stage, a biped just short of intelligence, whose purpose is to create more children. And there is the protector.

"At around age forty-two, our time, the breeder stage gets the urge to eat the root of a certain bush. Up to then he stayed away from it, because its smell was repugnant to him. Suddenly it smells delicious.

The bush grows all over the planet; there's no real chance that the root won't be available to any breeder who lives long enough to want it.

"The root initiates certain changes, both physiological and emotional. Before I go into detail, I'll let you in on the big secret. The race I speak of calls itself-" The Brennan-monster clicked its h.o.r.n.y beak sharply together. Pak. Pak. "But we call it "But we call it h.o.m.o habilis." h.o.m.o habilis."

"What?" Nick seemed forced into the position of straight man, and he didn't like it. But Luke sat hugging his useless legs to his chest, grinning with huge enjoyment.

"There was an expedition that landed on Earth some two and a half million years ago. The bush they brought wouldn't grow right, so there haven't been any protector stage Pak on Earth. I'll get to that.

"When a breeder eats the root, these changes take place. His or her gonads and obvious s.e.xual characteristics disappear. His skull softens and his brain begins to grow, until it is comfortably larger and more complex than yours, gentlemen. The skull then hardens and develops a bony crest. The teeth fall out, whatever teeth are left; the gums and lips grow together and form a hard, almost flat beak. My face is too too flat; it works better with flat; it works better with h.o.m.o habilis. h.o.m.o habilis. All hair disappears. Some joints swell enormously, to supply much greater leverage to the muscle. The moment arm increases, you follow? The skin hardens and wrinkles to form a kind of armor. Fingernails become claws, retractile, so that a protector's fingertips are actually more sensitive than before, and better toolmakers. A simple two-chamber heart forms where the two veins from the legs, whatever the h.e.l.l they're called, join to approach the heart. Notice that my skin is thicker there? Well, there are less dramatic changes, but they all contribute to make the protector a powerful, intelligent fighting machine. Garner, you no longer seem amused." All hair disappears. Some joints swell enormously, to supply much greater leverage to the muscle. The moment arm increases, you follow? The skin hardens and wrinkles to form a kind of armor. Fingernails become claws, retractile, so that a protector's fingertips are actually more sensitive than before, and better toolmakers. A simple two-chamber heart forms where the two veins from the legs, whatever the h.e.l.l they're called, join to approach the heart. Notice that my skin is thicker there? Well, there are less dramatic changes, but they all contribute to make the protector a powerful, intelligent fighting machine. Garner, you no longer seem amused."

"It all sounds awfully familiar."

"I wondered if you'd spot that. . . . . The emotional changes are drastic. A protector who has bred true feels no urge except the urge to protect those of his blood line. He recognizes them by smell. His increased intelligence does him no good here, because his hormones rule his motives. Nick, has it occurred to you that all of these changes are a kind of exaggeration of what happens to men and women as they get older? Garner saw it right away." The emotional changes are drastic. A protector who has bred true feels no urge except the urge to protect those of his blood line. He recognizes them by smell. His increased intelligence does him no good here, because his hormones rule his motives. Nick, has it occurred to you that all of these changes are a kind of exaggeration of what happens to men and women as they get older? Garner saw it right away."

"Yes, but-"

"The extra heart," Luke broke in. "What about that?"

"Like the expanded brain, it doesn't form without tree-of-life. After fifty, without modem medical care, a normal human heart becomes inadequate. Eventually it stops."

"Ah."

"Do you two find this convincing?"

Luke was reserving judgment. "Why do you ask?"

"I'm really more interested in convincing Nick. My Belt citizenship depends on my convincing you I'm Brennan. Not to mention my bank account and my ship and cargo. Nick, I've got an abandoned fuel tank from the Mariner XX attached to my ship, which I last left falling across the solar system at high speed."

"It's still doing that," said Nick. "Likewise the Outsider ship. We ought to be doing something about recovering it."

"Finagle's eyes, yes! yes! It's not that good a design, I could improve it blindfold, but you could buy Ceres with the monopoles!" It's not that good a design, I could improve it blindfold, but you could buy Ceres with the monopoles!"

"First things first," Garner said mildly.

"That ship is receding, Garner. Oh, I see what you mean; you're afraid to put an alien monster near a working s.p.a.cecraft." The Brennan-monster glanced back at the flare gun, flickeringly, then apparently abandoned the idea of hijacking the dustboat. "We'll stay out here until you're convinced. Is that a deal? Could you get a better deal anywhere?"

"Not from a Belter. Brennan, there is considerable evidence that man is related to the other primates of Earth."

"I don't doubt it. I've got some theories."

"Say on."

"About that lost colony. A big ship arrived here, and four landing craft went down with some thirty protectors and a lot of breeders. A year later the protectors knew they'd picked the wrong planet. The bush they needed grew wrong. They sent a message for help, by laser, and then they died. Starvation is a normal death for a protector, but it's usually voluntary. These starved against their will." There was no emotion in the Brennan-monster's voice or mask-like face.

"They died. The breeders were breeding without check. There was endless room, and the protectors must have wiped out any dangerous life forms. What happened next has to be speculation. The protectors were dead, but the breeders were used to their helping out, and they stayed around the ships."

"And?"

"And the piles got hot without the protectors to keep them balanced. They had to be fission piles, given the state of the art. Maybe they exploded. Maybe not. The radiation caused mutations resulting in everything from lemurs to apes and chimpanzees to ancient and modern man.

"That's one theory," said the Brennan-monster. "Another is that the protectors deliberately started breeding mutations, so that breeders would have a chance to survive in some form until help came. The results would be the same."

"I don't believe it," said Nick.

"You will. You should now. There's enough evidence, particularly in religions and folk tales. What percentage of humanity genuinely expects to live forever? Why do so many religions include a race of immortal beings who are constantly battling one another? What's the justification for ancestor worship? You know what happens to a man without modern geriatrics: as he ages his brain cells start to die. Yet people tend to respect him, to listen to him. Where do guardian angels come from?"

"Race memory?"

"Probably. It's hard to believe a tradition could survive that long."

"South Africa," said Luke. "They must have landed in South Africa, somewhere near Olduvai Gorge National Park. All the primates are there."

"Not quite. Maybe one ship landed in Australia, for the metals. You know, the protectors may have just scattered radioactive dust around and left it at that. The breeders would breed like rabbits without natural enemies, and the radiation would help them change. With all the protectors dead, they'd have to develop new shticks. Some got strength, some got agility, some got intelligence. Most got dead, of course. Mutations do."

"I seem to remember," said Luke, "that the aging process in man can be compared to the program running out in a s.p.a.ce probe. Once the probe has done its work it doesn't matter what happens to it. Similarly, once we pa.s.s the age at which we can have children-"

"-Evolution is through with you. You're moving on inertia only, following your course with no corrective mechanisms." The Brennan-monster nodded. "Of course the root supplies the program for the third stage. Good comparison."

Nick said, "Any idea what went wrong with the root?"

"Oh, that's no mystery. Though it had the protectors of Pak going crazy for awhile. No wonder a small colony couldn't solve it. There's a virus that lives in the root. It carries the genes for the change from breeder to protector. It can't live outside the root, so a protector has to eat more root every so often. If there's no thallium in the soil, the root still grows, but it won't support the virus."

"That sounds pretty complicated."

"Ever work with a hydroponics garden? The relationships in a stable ecology can be complicated. There was no problem on the Pak world. Thallium is a rare earth, but it must be common enough among all those Population II stars. And the root grows everywhere."

Nick said, "Where does the Outsider come in?"

A hiss and snap of beak: Phssth-pok. Phssth-pok. "Phssthpok found old records, including the call for help. He was the first protector in two and a half million years to realize that there was a way to find Sot, or at least to narrow the search. And he had no children, so he had to find a Cause quick, before the urge to eat left him. That's what happens to a protector when his blood line is dead. More lack of programming. Incidentally, you might note the heavy protection against mutation in the Pak species. "Phssthpok found old records, including the call for help. He was the first protector in two and a half million years to realize that there was a way to find Sot, or at least to narrow the search. And he had no children, so he had to find a Cause quick, before the urge to eat left him. That's what happens to a protector when his blood line is dead. More lack of programming. Incidentally, you might note the heavy protection against mutation in the Pak species.

A mutation doesn't smell right. That could be important in the galactic core, where radiation is heavy."

"So he came barreling out here with a hold full of seeds?"

"And bags of thallium oxide. The oxide was easiest to carry. I wondered about the construction of his ship, but you can see why he trailed his cargo section behind his lifesystem. Radiation doesn't bother him, in small amounts. He can't have children."

"Where is he now?"

"I had to kill him."

"What?" Garner was shocked. "Did he attack you?"

"No."

"Then-I don't understand."

The Brennan-monster seemed to hesitate. It said, "Garner, Sohl, listen to me. Twelve miles from here, some fifty feet under the sand, is part of an alien s.p.a.cecraft filled with roots and seeds and bags of thallium oxide. The roots I can grow from those seeds can make a man nearly immortal. Now what? What are we going to do with them?"

The two men looked at each other. Luke seemed about to speak, closed his mouth.

"That's a tough one, right? But you can guess what Phssthpok expected, can't you?"

Phssthpok dreamed.

He knew to within a day just how long it would take for Brennan to wake up. He could have been wrong, of course. But if he were, then Brennan's kind would have mutated too far from the Pak form.

Knowing how long he had, Phssthpok could time his dreaming. The martians were no threat now, though something would have to be done about them eventually. Dreaming was a fine art to a protector. He had about ten days. For a week he dreamed the past, up until the day he left the Pak planet. Sensory stimulation had been skimpy during the voyage. He moved on into the future.

Phssthpok dreamed.

It would begin when his captive woke. From the looks of him, the captive's brain would be larger than Phssthpok's; there was that frontal bulge, ruining the slope of the face. He would learn fast. Phssthpok would teach him how to be a protector, and what to do with the roots and seeds of tree-of-life.

Did the breeder have children? If so, he would take the secret for his own, using tree-of-life to make protectors of his own descendants. That was all right. If he had sense enough to spread his family around, avoiding inbreeding, his blood line should reach out to include most of this system's Pak race.

Probably he would kill Phssthpok to keep the secret. That was all right too.

There was a nightmare tinge to Phssthpok's dreaming. For the captive didn't look right. His fingernails were developing wrong. His head was certainly not the right shape. That frontal bulge . . . . . . and his beak was as flat as his face had been. His back wasn't arched, his legs were wrong, his arms were too short. His kind had had too much time to mutate. and his beak was as flat as his face had been. His back wasn't arched, his legs were wrong, his arms were too short. His kind had had too much time to mutate.

But he'd reacted correctly to the roots.

The future was uncertain . . . . . . except for Phssthpok. Let the captive learn what he needed to know, if he could; let him carry on the work, if he could. There would come a day when Earth was a second Pak world. Phssthpok had done his best. He would teach, and die. except for Phssthpok. Let the captive learn what he needed to know, if he could; let him carry on the work, if he could. There would come a day when Earth was a second Pak world. Phssthpok had done his best. He would teach, and die.

Brennan stirred. He unfolded his curled body, stretched wide and opened his eyes. He stared unwinking at Phssthpok, stared as if he were reading the protector's mind. All new protectors did that: orienting themselves through memories they were only now beginning to understand.

"I wonder if I can make you understand how fast it all was," said the Brennan-monster. He gazed at the two old men, one twice the age of the other but both past the transition age, and wondered that they should be his judges.

"In two days we learned each other's language. His is much faster than mine and fits my mouth better, so we used it. He told me his life story. We discussed the martians, working Out the most efficient way to exterminate them-"

"What?"

"To exterminate them, Garner. h.e.l.l, they've killed thirteen men already! We talked practically nonstop, with Phssthpok doing most of the talking, and all the time we were hard at work: calisthenics to build me up, fins for Phssthpok's suit so he could swim the dust, widgets to get every atom of air and water out of the life support system and take it to the base. I've never seen the base; we had to extrapolate the design so we'd know how to re-inflate it and protect it.

"The third day he told me how to get a tree-of-life crop growing. He had the box open and was telling me how to unfreeze the seeds safely. He was giving me orders just as if I were a voice-box computer. I was about to ask, 'Don't I get any choices at all?' And I didn'L" didn'L"

"I don't follow," said Garner.

"I didn't get any choices. I was too intelligent. It's been that way ever since I woke up. I get answers before I can finish formulating the question. If I always see the best answer, then where's my choice? Where's my free will? You can't believe how fast this all was. I saw the whole chain of logic in one flash. I slammed Phssthpok's head hard against the edge of the freezer. It stunned him long enough so that I could break his throat against the edge. Then I jumped back in case he attacked. I figured I could hold him off until he strangled. But he didn't attack. He hadn't figured it out, not yet."

"It sounds like murder, Brennan. He didn't want to kill you?"

"Not yet. I was his shining hope. He couldn't even defend himself for fear of bruising me. He was older than me, and he knew how to fight. He could have killed me if he'd wanted to, but he couldn't want to. It took him thirty-two thousand years of real time to bring us those roots. I was supposed to finish the job.

"I think he died believing he'd succeeded. He half-expected me to kill him."