“Pity you didn’t fit it out with wings,” Matthew commented, although he knew perfectly well why bio-inspired design ran into severe practical limitations when it came to mimicking the mechanisms of flight. Locusts and herons were near-miraculous triumphs of engineering; the only ornithopter produced on twenty-first-century Earth that had been capable of carrying a human passenger had been the ungainliest machine ever devised. If the engineers of twenty-ninth-century Earth had been able to improve on it, the secret hadn’t yet been passed on to the crew of Hope.

“We had to keep it simple,” Lynn told him. “Going downstream will be easy, though, provided that the biomotor finds the locally derived wholefood adequate to its needs. The real trial will begin when we turn around to come back. Coming back under our own power will test the boat’s resources to the limit. We can arrange for an emergency food and equipment drop from Hopeif we need one, and maybe some sort of rescue mission if things get really desperate, but there are matters of pride to be considered. She’s our baby—we want her to do well.”

Everyone but Maryanne Hyder was on the riverbank to see them off, and the good-byes seemed reasonably effusive by comparison with the awkward hellos that had greeted Matthew a couple of days earlier.

Rand Blackstone made a considerable fuss about presenting his rifle to Matthew. “I won’t need it up here,” he said. “You might.”

“Why give it to me rather than one of the others?” Matthew asked.

“I used to watch you on TV,” the Australian told him. “I could see that you got out and about at lot, sometimes in dangerous places. You didn’t live in a lab like Ike or Lynn. Besides which, I’ve seen the others try to shoot. Your reflexes may not be attuned yet, but you can’t be any worse than them. I ought to be going with you, of course—but Delgado was insistent that he needed educated eyes. Mine didn’t qualify, apparently.”

“Nor would mine,” Vince Solari told him, belatedly beginning the work of cultivating a sense of camaraderie with his new neighbors.

“Good luck,” was all that Godert Kriefmann said, but Tang was more forthcoming.

“I hope you have a productive journey,” the biochemist said. “If you can’t bring back the answers to the big questions, I’m sure you’ll make good progress on some of the smaller ones.”

Matthew took Vince Solari aside so that he could speak to him in confidence: “Is there anything you want to tell me?” he asked.

Solari was still sulking. “No,” he said. “We can always compare notes by phone, if necessary.”

“While we’re still sailing down the river, at least,” Matthew said. “Once we head off into the glassgrass forest, it might become more difficult. If our beltphones don’t have enough power to force a signal through the canopy that’s strong enough for the comsats to unscramble, they might not have much sideways range either. At least one of us will stay with the boat at all times, but keeping in touch with them might become a problem.”

“Have you complained to Milyukov about that?” Solari said. “It seems stupid to send you on an exploratory mission without adequate equipment.”

“Of course I did,” Matthew replied, sourly. “He assured me that better equipment was on standby, ready to drop at a moment’s notice in any emergency. I think he’d rather we didn’t stray too far into terra incognita. He’d rather we didn’t find anything too exotic while he’s still trying to reach a satisfactory agreement with the people at Base One, and doesn’t want to give broadcasting equipment to anyone down here in case they start putting out propaganda for Tang’s party. I’m sorry you didn’t get to arrest your murderer.”

“I will,” Solari assured him. He seemed more confident of that now than he had the previous evening. “And by the time you get back, I’ll have some kind of due process in place to carry the case forward.”

“So you are convinced that it’s one of my fellow expeditionaries.”

“Absolutely—but that should be the least of yourworries. If you get through the canyons and past the cataract, you’ll still have all the unknown perils in front of you. If the plain is a potential death trap, I hope you’ll be quick enough on the uptake not to spring it.”

“Thanks,” Matthew said, drily.

After that, there was only the farewell waving to be done. Blackstone was the only one of the people left behind on the shore who was an enthusiastic waver, but that was probably because no one else cared to compete with the majestic sweeps of his hat.

The biomotor was silent, and it seemed at first that they were simply drifting on a leisurely current. Once they were comfortably set in the middle of the watercourse, though, Matthew became aware of the fact that Voconia’s hull wasn’t rigid, and that it was undergoing slight but distinct undulations in a horizontal plane.

“It’s swimming!” he said to Ikram Mohammed, who had joined him in the bow to watch the water go by.

“Not really,” Ike told him. “It’s just making minimal adjustments to reduce flow-resistance. Swimming would have required more elaborate musculature and more energy-rich food. Even if the fuel-consumption equations had added up better we’d have had to go to some trouble to rig the converters to produce the stuff. The kit we’ve got isn’t fussy, so we’ve been able to put the vegetation we cleared with machetes and chain saws straight into the machine for minimal treatment. It saved us the trouble of amassing huge waste heaps.”

Matthew leaned over the rail and peered at the water, hoping to catch sight of a few native swimmers whose fuel-consumption equations added up better than Voconia’s, but the sunlight reflected from the wave-stirred surface made it impossible to see much below the surface.”

“If we hit quiet water around dusk you might be able to see top-feeders at work,” Ike told him. “Otherwise, they’re very discreet. I tried fishing with a rod and line back at the base, but I must have been using the wrong bait. We’ve deployed a couple of trail nets, but they didn’t pick up much on the test runs. You’ll stand a better chance of spotting interesting wildlife if you scan the vegetation on the bank. You’ll see lizards, mammals. This green color seems garish to us, but it doesn’t seem to alarm the natives unduly, even though the clever ones do have color vision. The local species don’t seem to go in for warning coloration—camouflage is much more popular.”

Matthew discovered soon enough that Ike was right. It was possible to catch glimpses of animal life at the water’s edge, but glimpses were all he caught. There were no hawks circling in the sky, but there were presumably sharp-eyed predators lurking in the abundant undergrowth, ever-ready to creep up on any prey that displayed itself too flagrantly in the open. As time went by he became more expert in picking out the particular purples displayed by the scales of reptile-analogues. Once or twice he thought he recognized the darker shades of purple favored by the fur of mammal-equivalents, but he couldn’t be sure. The hectic background was too confusing to permit much certainty of perception.

After a while he tried to stop sorting out shades of purple and concentrated on trying to locate black dots that might be staring eyes, but that only made it slightly easier to pick out the bigger reptilians. As Ike had predicted, the lizard-analogues seemed quite unworried by the passage of the green boat, although many of them turned their heads in what seemed to be a negligent manner to watch it drift downriver. Matthew couldn’t help wondering whether they were at all curious about its nature or origins, and whether it would be any easier to read the expressions of the mammal-analogues if and when he got a chance to do so.

Matthew clung to his position in Voconia’s bow for more than two Earthly hours, determined to obtain a better sense of the nature of the riverside forests and their inhabitants. The shallows, mudflats and occasional marshlands were full of broad-leaved plants that would not have seemed un-Earthlike had it not been for their color, but the firmer ground was more exotically populated.