"Sure there is," Yerby said. "Nothing we need to worry about, though. They're mostly birds-that's why the pooler was scared of our flyers. Some of the really biggest ones, they run on the ground, but even they used to be birds before they got too big to fly. You'd need to go a good five hundred miles south to find any of them anyways."

"I was just curious," Mark said. It wasn't entirely a lie.

"Yerby, you're right," said Amy, looking up at the waterfall sliding through the air in rainbow splendor. "This place is beautiful. The whole planet is."

Yerby beamed as though she'd praised him personally. "Ain't it, though?" he said. "You know? I'd like to keep it like this."

"This corner?" Amy said. "This waterfall, you mean."

Yerby shook his head and grimaced. "Look, I know it don't make sense, but I'd like to keep Greenwood pretty much the way it is. You know, I just come back from Kilbourn and the way it's built up-that's too many people."

"How big is Kilbourn?" Mark asked sharply. He was trying to connect this Yerby Bannock with the man who let freshets flush his garbage into the river.

"About a million and a half," Amy said. She looked surprised also. "The population's been growing fast all through my lifetime, ever since the Treaty of Cozumel."

"And yeah, I know what you're thinking, Mark," Yerby said. "I could do a better job keeping things neat than I do. But hell, people ain't perfect, and the more of them you put together the worse they each of them gets. There's cities on Kilbourn so crowded I wouldn't board a dog there."

And how would you feel about Landingplace or Zenith's capital, New Paris? Mark thought. Aloud he said, "You know, I think a recycling plant could pay for itself in a year or two. A few years."

"Have you talked about this with Dr. Jesilind?" Amy said. "His vision for Greenwood is huge city-buildings, arcologies, like they have on Earth. Everything self-contained, everyone living in identical boxes with identical parks and artificial rain at programmed times."

Yerby shook his head glumly, looking out over the savannah. "I know," he said. "He's a smart man, the doc is, educated like I'll never be. Only…"

The big man leaned down and thrust his hand like a spade into the hole from which he'd plucked the grass. He crumbled the loam through his fingers. "Thing is," Yerby said softly, "there's plenty of planets. No reason to put a lot of folks on every one of them. And there's plenty already built up now, like Kilbourn. Some folks, that's how they want to live."

He scattered the last of the black dirt at his feet and straightened. "Kilbourn, it's not going to go away. Earth's not going to go away. People who want to live tight together already have plenty of places to do that. There's other folks who need to be able to stick their fingers in the dirt and look at a waterfall with just a couple friends. I'd like Greenwood to stay a place you could do that."

He laughed uncomfortably. "Well, I guess I sound pretty silly to a couple educated people like you, don't I? Don't know what came over me to talk like that."

"I didn't hear anything silly," Mark said quietly. He squatted and rubbed bare dirt between his thumb and forefinger. "You know," he added, "it could be that more people need the chance to sit with a few friends and a lot of nature than know they do."

The pooter stuck its head out of the hole again. Mark winked at it. After a moment, the creature snipped off a clump of grass and began to ingest it, bite by bite.

As they watched the creature eat, Yerby Bannock said, "Where d'ye suppose a man would find one of them recycling plants you talked about, Mark lad?"

As the flyers rose above the ridgeline, their motors running strongly in the midafternoon sunlight, the tiny radio attached to the hub of Amy's control yoke crackled, "-need help soonest. I got a gang of Zenith surveyors and their ship parked in my soybeans. Anybody who can hear me, come lend a hand. This is Dagmar Wately and I need help! Over."

"This is Yerby Bannock, Dagmar," the speaker resumed instantly. Mark could hear Yerby's voice faintly from the flyer ahead of them a beat or two after the same words had arrived over the radio. "I'm about ten minutes out. Anybody who can hear my signal, grab a persuader and come help Dagmar Wately talk to some Zeniths in her soybean field. That's southwest of her compound. Out!"

Yerby banked his flyer, swinging west by northwest from the south heading he'd set to go home. He bellowed over his shoulder, "You kids get back to the compound. Send George and Elmont out to Dagmar's soybeans if they haven't already gotten the message."

Amy continued to pull her craft around to follow her brother. She looked at Mark in an unspoken question.

"I don't know what I can do to help him," Mark said, "but I wouldn't feel right not to try."

Amy smiled. "Thanks," she said. "For not telling me I'm a girl."

"You are a girl," Mark said. "But I don't see that you can be much more useless than I am."

Amy's laugh trilled merrily across the sky. She held station a little above and behind her brother's flyer, just as she had on the way north. Yerby looked back at them and glared, but he didn't waste his breath shouting further orders.

Nearly a thousand acres of soybeans filled a valley similar to the one from which Mark and his friends had just come. The Terran crop was a green with less gray in it than the native vegetation growing near rock outcrops that hadn't been plowed. The starship sat like a troll in the midst of the rolling field on four great outrigger pontoons.

Frequent heating and cooling by magnetic eddy currents colored the upper surfaces of the ship's spherical hull. The lower curves were blackened by carbon not from the rocket fuel-that was surely hydrogen and oxygen-but from the loam and vegetation that the exhaust had incinerated as it blew a crater in the field on landing.

A handful of air-cushion jeeps, each holding two people in orange coveralls, drove across the field. One of them was nearly a mile from the starship. The survey party was setting fluorescent white rods in the ground at intervals of several hundred yards.

The starship's main hatch was lowered to the ground. A flyer like the Bannocks' sat close by. A figure in Greenwood leather waved as she argued on the boarding ramp with three figures in tailored white uniforms. Several other flyers approached in the clear sky, but none of them were as close as the Bannock craft.

Yerby landed at the edge of the ramp. Amy came down a fraction of a second behind him, dropping from the sky with a verve that left Mark's stomach fifty feet behind. The flyer's frame flexed dangerously. Mark tried to take some of the shock on his own legs and managed to bury his feet ankle-deep in the soft field.

"Amy, child," Yerby said as he got out of his flyer's space-framed cockpit, "why don't you stick by the radio and relay things to the neighbors flying in. I'd like them to stay in the air just for now."

He didn't look back at the other flyer. Mark hadn't seen Yerby unstrap the heavy flashgun from his rack, but it was cradled now in the crook of his left arm. The weapon's squat barrel, a Cassegrain laser, was six inches in diameter and only a foot long.

Mark stayed a pace behind and to the left as Yerby strolled up the ramp toward the four waiting figures. "'Lo, Dagmar," Yerby said. Even standing below them on the slope, he was as tall as any of the three Zeniths, two men and a woman. "Like you to meet Mark Maxwell, a friend of mine. Gather you've got a problem here?"

Dagmar Wately was younger than Desiree but of similar build. She wore leather breeches and a jacket whose loops and pockets were full of tools. She thumbed toward the uniformed trio. "I come out when I heard them land," she said. "Thought they might be in trouble. Seems they're from Zenith and they think they got a right to be here."