It felt the pressure of its own weight for the first time in its life.

How could it feel weaker and more powerful at the same time?

Something even stranger happened. It turned, humping its body sideways in sudden alarm. One of its siblings was coming, dull black eyes fixed hungrily. It smelled wrong... smelled right. There was no image, no feeling to match this smell, but something within the swimmer began to flare. It felt suddenly weightless, no longer clumsy...

Its sibling lunged forward.

All thought was overwhelmed by its instinctive response. The swimmer flopped to the side, and the strike of its sibling caught only air. The swimmer's head whipped around and it sank new teeth into its attacker's flank.

Never before had it fought one of its own. The only memory of survival stress was the struggle to evade the Big One, the One who ate swimmers. Many times the Big One had come, and the swimmer had moved swiftly. More swiftly than many of its siblings, because this swimmer had survived.

Once, the Big One had hung quiescent in the water, exuding a different smell. The swimmer had drawn closer, closer, unable to retreat. So close that the Big One could have caught it easily if it wished.

There followed a moment of such intensity that the swimmer could not clearly remember what had happened.

This moment held similar intensity: fear and rage and the taste flaring in its mouth and brain.

The sibling tried to retreat now, but the swimmer was suddenly ravenous. It had tasted something more delicious than all of the green muck in the world. It struck again and again. Around it, other siblings were joining in. They ripped and tore. The smell of blood filled its senses. The death agonies of its hapless sibling quieted, until at last there was nothing but the feast...

Tau Ceti wavered in the mist, stared out at Cadmann like a bloodshot eye. Vanished behind a strand of horsemane trees. Back, then gone again as the Skeeter skimmed the stream.

The swamp below him swarmed with grendels. He couldn't see individuals yet, but he saw darting streaks everywhere. Trees and brush and shrubbery shook, churned and chewed by the horde.

Carlos touched his shoulder. "Amigo. Como esta?"

"Bien. Y usted?"

"Jitters. Cramps." Carlos gripped at his stomach. "The stress is not sweet. But I think I will make fewer mistakes."

"That's the picture. And from here on out, we can't afford any mistakes at all." Cadmann brought the Skeeter down closer to the river. Now he could make out individual grendels. They crowded the water like catfish in the breeding pond, writhing and biting at each other. Two chased a third up a horsemane tree. The leader was too slow, too clumsy. It lost its grip and fell; the others snapped at it as it passed, and the three fell in a writhing cluster.

"Carlos, you're more the mathematician than I am. What is the minimum survival population for our colony?"

"We worked that out. I read a paper on it once. Minimum genetic diversity, minimum skill spread. We took the minimum in adults, with three times that many in fetuses. But if one has faith in the Good Book, one man and one woman could repopulate a planet."

"Times like this, faith isn't a terrible idea." Cadmann grinned bleakly. He directed the Skeeter's camera to the knot of writhing grendels beneath them.

"Feeding frenzy. They trigger on their own. Let's see what Jerry's idea does." Carlos clipped the wire fastened just inside the door. One of the weighted sacks hanging from the side of the Skeeter dropped. Calf blood spilled into the water.

The grendels went crazy. They bit at nothing, drunken with blood lust.

The water churned black.

"Damn, they're stupid."

"Yeah, but they're infants. The ones who survive will be smarter—and we don't have an unlimited supply of calf blood. The reflex is there, though. That's encouraging. We have a pretty creative group. Someone will come up with something even better."

They died by the hundreds. Chewed corpses floated belly up, choking the surface. Others moved in to feed.

"They are no longer fighting," Carlos said.

"No. Enough to eat? Something. Still, we got a lot of them." Cadmann's smile was grim. "Come on. We have work to do."

As they pulled up over the Colony, Minerva Two rose from the dam on a column of foam and mist. Cadmann hovered there, as thousands of gallons of water cascaded back into the lake with a thunderous roar. Waves crashed out in concentric rings, pounding at the dock.

The two friends watched the craft climb. It had vanished into the mist before the sound changed from one kind of thunder to another as the nuclear ramjet lit.

"I don't think I want to be behind a Minerva when it takes off," Carlos said.

"Nor I. How can we entice grendels to cluster there?"

"That's what I was thinking—"

"When you think of a way, be sure it's safe. Without the Minervas we're dead."

They circled the camp. Its fortifications lay spread out below like a tabletop model.

The electric fence had a new, larger twin within the moat of mines.

The outer fields had been harvested, the grain shipped up to the Bluff. Tractors under remote control chugged slowly in the barren fields. Cadmann could distinguish the flamethrower nozzles welded to the fronts of the cultivators and irrigators.

The welding lasers, the torches, the plasma drills were all arrayed as weapons now. Virtually every tool from engineering had been modified to the defense of the Colony.

He could see the gunmen too, but he knew where they were beforehand: stationed at the corners of the fence, ready to fire along its length. Skeeters moved about, swooping to fire at grendels. There were not so many grendels yet, but they all had to be stopped before they reached the fences.

"I still say it's chancy," Cadmann murmured.

"Eh?"

"Both Minervas in flight. No power for the fences while they're both up. Lose both and we're dead."

"So why did you let them both go up?"

"Schedule. Sometimes you just have to take chances. It doesn't mean I like it."

They circled over stacks of thornwood faggots stacked at intervals, wired for ignition at command. "I hope it works," Cadmann said.

Carlos shrugged. "Jerry and Marnie swore by this. Do you trust them?"

"I trust the logic. Add heat to an already overheated grendel and watch it cook. I trust them. I'm just not sure I believe it."

The cattle and horse pens were empty. Cadmann could see the occupants moving uphill, horsemen and horsewomen on the outskirts of the herds: old movies played through his mind. We've got rustlers like you never dreamed of, Duke.

Cadmann settled the Skeeter lightly to the pad. As he unbuckled his safety belt, Zack opened the door.

"I thought you'd be aboard Geographic by now." Cadmann pulled the tape cartridge from the camera.

Zack said, "Nope. Not yet. I don't really want to go, you know."

"Yeah, and I don't really want to stay. People like you and me don't get a whole lot of choice in life. How is everything going?"

"Rachel says that the work shifts were implemented just fast enough. Everyone's so tired that the shock hasn't had a chance to sink in yet. When it does..."

"By the time that it does, this will be over, one way or the other."

A loud, miserable bray from the center of camp caught Cadmann's attention. "Damn!"

"Huh?"

"The horses. Let them go. The grendels aren't fully mature. The horses may be able to outrun them. A few may survive."

"Bloody unlikely."

"Yeah, but as the man said—the grendels are running for their lunch—"

"The horses are running for their lives. Got it. Besides," Carlos said soberly, "I'm sure they would rather die on the run than trapped in a pen." He looked thoughtful for a moment. "They would have a better chance if someone went with them. To guide them. Take them as high as possible."