“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.”

“Brennan. Why?”

The Brennan-monster shrugged cantaloupe shoulders. “He was wrong. I killed him because he would have tried to wipe out humanity when he learned the truth.” He reached into the slit balloon that had brought him across twelve miles of fluid dust. He pulled out a jury-rigged something that hummed softly — his air renewal setup, made from parts of Phssthpok’s control board — and dropped it in the boat. Next he pulled out half of a yellow root like a raw sweet potato. He held it under Garner’s nose. “Smell.”

Luke sniffed. “Pleasant enough. Like a liqueur.”

“Sohl?”

“Nice. How’s it taste?”

“If you knew it would turn you into something like me, would you take a bite of it? Garner?”

“This instant. I’d like to live forever, and I’m afraid of going senile.”

“Sohl?”

“No! I’m not ready to give up sex yet.”

“How old are you?”

“Seventy-four. Birthday two months from now.”

“You’re already too old. You were too old at fifty; It would have killed you. Would you have volunteered at forty-five?”

Sohl laughed. “Not likely.”

“Well, that’s half the answer. From Phssthpok’s point of view we’re a failure. The other half is that no sane man would turn the root loose on Earth or Belt or anywhere else.”

“I should hope not. But let’s hear your reasons.”

“War. The Pak world has never been free from war at any time in its history. Naturally not, with every protector acting to expand and protect his blood line at the expense of all the others. Knowledge keeps getting lost. The race can’t cooperate for a minute beyond the point where one protector sees an advantage in betraying the others. They can’t make any kind of progress because of that continual state of war.

“And I’m to turn that loose on Earth? Can you imagine a thousand protectors deciding their grandchildren need more room? Your eighteen billion flatlanders live too close to the edge already; you can’t afford the resources.

“Besides which, we don’t really need tree-of-life. Garner, when were you born? Nineteen forty or thereabouts?”

“Thirty-nine.”

“Geriatrics is getting so good so fast that my kids could live a thousand years. We’ll get longevity without tree-of-life, without sacrificing anything at all.

“Now look at it from Phssthpok’s viewpoint,” the Brennan-monster continued. “We’re a mutation. We’ve settled the solar system and started some interstellar colonies. We will and must refuse the root, and even when it’s forced on us, the resulting mutated protectors are atypical. Phssthpok thought in terms of the long view. We’re not Pak, we’re no use to the Pak, and it’s conceivable that someday we’ll reach the core suns. The Pak will attack us the moment they see us, and we’ll fight back.” He shrugged. “And we’ll win. The Pak don’t unite effectively. We do. We’ll have a better technology than theirs.”

“We will?”

“I told you, they can’t keep their technology. Whatever can’t be used immediately, gets lost until someone files it in the Library. Military knowledge never gets filed; the families keep it a deep, dark secret. And the only ones to use the Library are childless protectors. There aren’t many of them, and they aren’t highly motivated.”

“Couldn’t you have tried to talk to him?”

“Garner, I’m not getting through to you. He’d have killed me the moment he figured it out! He was trained to fight protectors. I wouldn’t have had a chance. Then he’d have tried to wipe out the human species. We’d have been much worse to him than hostile aliens. We’re a corruption of the Pak form itself.”

“But he couldn’t do it. He was all alone.”

“I’ve thought of half a dozen things he could have tried. None of them sure things, but I couldn’t risk it.”

“Name one.”

“Plant tree-of-life all through Congo National Park. Organize the monkey and chimpanzee protectors.”

“He was marooned here.”

“He could have commandeered your ship. He’d have had your silly flare gun as fast as I did. Gentlemen, may I point out that it’s near sunset? I don’t think we want to navigate the ring wall in darkness.”

Luke started the motor.

“This is Martin Shaeffer at Ceres calling Nick Sohl aboard U Thant. Nick, I don’t know how your hunting goes, but Phobos reports that you’ve landed safely at Olympus Base, and they’re tracking your dustboat wake. Presumably you’ll find this on tape when you get back.

“We’ve sent the Blue Ox to meet you, on the theory that you may need the computer package as a translating device. Eisaku Ikeda commanding. The Ox should reach Olympus Base a day behind the UN fleet.

“Einar Nilsson is dead. We’ll have an autopsy report shortly.

“We’ve sent fuel ships and construction facilities to rendezvous with the Outsider ship. There are two singleships falling alongside already, and the Outsider ship has a tested tow line of its own. We may be able to rig the singleships for towing. Still, it’s all going to be very sticky and time consuming. We may not get it home to the Belt for a couple of years.

“Nick, when the Ox gets there, be careful of Tina Jordan. Don’t shake her up. She’s had a bad shock. I think she blames herself for what happened to Einar.

“Repeating…”

Luke docked the dustboat in near-darkness. He said, “You’ll have to wait in the boat, Brennan. Nick can’t carry us both.”

“I’ll roll,” said the Brennan-monster.

Nick’s walk down the path and around the rim of the dust pool was made in unseemly haste. “Take it easy,” Luke complained. “You can’t trot in this light. You’ll fall and crack both our helmets.”

“He’s going to beat us to the ship,” Nick said edgily.

Brennan was taking the short cut, rolling directly across the dust.

“Slow down. You can’t beat him, and he can’t get up the ladder.”

“Maybe he’s thought of a way. If he does… oh, hell.” Nick slowed down. Brennan had rolled uphill to the foot of U Thant’s ladder. He waited for them there like a translucent sausage.

“Nick? Do you trust him?”

It was seconds before he answered. “I think his story’s straight. He’s a Belter. Or an ex-Belter.”

“He swore by damn instead of by Finagle.”

“So do I. And he recognized me. No, I’ll tell you what really convinced me. He didn’t ask about his wife, because she can take care of herself. He asked about his cargo. He’s a Belter.”

“We accept his story, then. Anthropology and all. Wow.”

“His story, yes. Luke, I’ll take you up, then come back for Brennan. But I won’t come down until you’re talking to Ceres. I want all of this on record before I let him in the ship. I’m still wondering about his motives.”

“Ah.”

“He said it himself. Motives change for a protector.” Garner was already signing off when Brennan climbed out of his zippered balloon. Brennan made no mention of the delay. He said, “If you’re worried about accommodations, I can get along without an acceleration couch. In fact, I can ride outside in a cargo net if you’ll give me a radio link. If my patchwork air plant breaks down I’d want to get inside fast.”

“That won’t be necessary. It’ll be cramped, but not that cramped,” said Nick. He squeezed past Brennan, wincing inside himself from the dry leathery touch, and into the control chair. “We seem to have a message.”