“When did you find all that out?” Dalehouse was annoyed; the rule of the expedition was that each of them shared discoveries as soon as made.

“When you were bugged at me for being stoned out of my mind,” Morrissey said. “I think it has to do with the way they generate their hydrogen. Solar flares seem to be involved. So when they saw our lights they thought it was a flare — and that’s when they spawned. Only we happened to be underneath, and so we got sprayed with, uh, with—”

“I know what we got sprayed with,” Dalehouse said.

“Yeah! You know, Danny, when I took up this career they made dissecting specimens sound pretty tacky — but every time I go near one of the males’ sex glands I get high. I’m beginning to like this line of work.”

“Do you have to kill them all off to do it, though? You’ll chase the flock away. Then how am I going to make contact?”

Morrissey grinned. He didn’t answer. He just pointed aloft.

Dalehouse, in justice, had to concede the unspoken point. Whatever emotions the gasbags had, fear did not seem to be among them. Morrissey had shot down nearly a dozen of them, but ever since the first contact the swarm had almost always stayed within sight. Perhaps it was the lights that attracted them. In the permanent Klongan twilight, there was no such thing as “day.” The camp had opted to create one, marked by turning on the whole bank of floodlights at an arbitrary “dawn” and turning them off again twelve clock hours later. One light always stayed on — to keep off predators, they told themselves, but in truth it was to keep out the primordially threatening dark.

Morrissey picked up the balloonist. It was still alive, its wrinkled features moving soundlessly. Once down, they never uttered a sound — because, Morrissey said, the hydrogen that gave them voice was lost when their bags were punctured. But they kept on trying. The first one they had shot down had lived for more than forty hours. It had crept all around the camp, dragging its gray and wrinkled bag, and it had seemed in pain all of that time. Dalehouse had been glad when it died at last, was glad now when Morrissey plunged the new one into a killer bag for return to Earth.

Kappelyushnikov limped up to them, rubbing his buttocks. “Is always a martyr, first pioneer of flight,” he grumbled. “So, Danny Dalehouse. You want go up now?”

An electric shock hit Danny. “You mean now?”

“Sure, why not? Wind isn’t bad. I go with, soon as two balloons fill.”

It took longer than Dalehouse would have thought possible for the little pump to fill two batches of balloons big enough for human passengers — especially since the pump was a hastily rigged nonsparking compressor that leaked as much gas as it squeezed into the bags. Dalehouse tried to eat, tried to nap, tried to interest himself in other projects, and kept coming back to gaze at the tethered clusters of bags, quietly swelling with hydrogen, constrained by the cord netting that surrounded them.

The weather had taken a turn for the worse. Clouds covered the sky from horizon to horizon, but Kappelyushnikov was stubbornly optimistic. “Clouds will blow away. Is positive skies will be clear.” When the first pinkening of sky began to show, he said decisively, “Is okay now. Strap in, Danny.”

Mistrustfully, Dalehouse buckled himself into the harness. He was a taller but lighter man than the Russian, and Kappelyushnikov grumbled to himself as he valved off surplus hydrogen. “Otherwise,” he explained, “you go back to state of Michigan, East Lansing, shwoosh! But next time, not so much wasting gas.”

The harness had a quick-release latch at the shoulders, and Dalehouse touched it experimentally.

“No, no!” screamed Kappelyushnikov. “You want to pull when you are up two hundred meters, fine, pull! Is your neck. But don’t waste gas for nothing.” He guided Danny’s hands to the two crucial cords. “Is not clamjet, you understand? Is free balloon. Clamjet uses lift to save fuel. Here is no fuel, only lift. Here you go where wind goes. You don’t like direction, you find different wind. Spill water ballast, you go up. Spill wasserstoff, you go down.”

Dalehouse wriggled in the harness. It was not going to be very much like sailplaning over the eastern shore of Lake Michigan, where there was always a west wind to bounce off the bluffs and keep a glider aloft for hours. But if the Russian could do it, he could do it. I hope, he added to himself, and said, “All right, I think I have the hang of it.”

“So let’s go,” cried the Russian, grinning as he slipped into his own harness. He bent and picked up a fair-sized rock, gesturing to Danny to do the same. The other members of the expedition were standing back, but one of them handed Danny a rock, and at Kappelyushnikov’s orders they untethered the balloons.

Kappelyushnikov danced over toward Danny like a diver stilting across a sea bottom. He came as close as he could under the bulk of their balloons, peering into his face. “You are all right?” Danny nodded. “So drop the rock and we go!” Kappelyushnikov cried. And he cast his own rock away and began to float diagonally upward.

Dalehouse took a deep breath and followed his example, watching the Russian move upward.

Nothing seemed to happen. Danny did not feel any acceleration, only that his feet seemed to have gone abruptly numb and there was no sensation of pressure on their bottoms. Because his eyes were on Kappelyushnikov he neglected to look down until he was fifty meters in the air.

They were drifting south, along the coastline. Far above them and inland, over the purple hills that marked the edge of the fern forest, the extended swarm of balloonists was grazing on whatever tiny organisms they could find floating in the sky. Below and behind was the dwindling campsite. Danny was already higher than the nose of their return rocket, the tallest object in camp. Off to his left was the sea itself, and a couple of islands in the muddy waters, covered with many-trunked trees.

He wrenched his attention away from sight-seeing; Kappelyushnikov was shouting at him. “What?” Dalehouse bellowed. The gap had widened; Gappy was now forty meters above him and moving inland, evidently in a different air layer.

“Drop… little… water!” shouted the Russian.

Dalehouse nodded and reached tentatively for the valve cord. He pulled at it with a light touch.

Nothing happened.

He pulled again, harder. Half a liter of ballast sprayed out of the tank, drenching him. Danny had not realized that the passenger was directly under the ballast tank, and gasping, he vowed to change that element of design before he went up again.

But he was flying!

Not easily. Not with grace. Not even with the clumsy control that Kappelyushnikov had taught himself. He spent the first hour chasing Gappy across the sky. It was like one of the fun-house games where you and your girl are on different rotating circles of a ride, when neither of you can take a step except to change from one spinning disk to another. Though Kappelyushnikov did all he could to make capture easy, he never caught the Russian — not that first time.

But — flying! It was exactly the dream he had always had, the dream everyone has had. The total conquest of the air. No jets. No wings. No engines. Just gently swimming through the atmospheric ocean, with no more effort than floating in a saltwater bay.

He reveled in it, and as time went on — not in the first flight or the tenth, but the supply of hydrogen was limitless, if slow in coming, and he made as many flights as he could — he began to acquire some skill.

And the problem of reaching the gasbags turned out to be no problem at all.

He didn’t have to seek them out. They were far more skilled at flying than he, and they came to him, bobbing around like great jack-o’-lanterns with hideous ticklike faces, peering inquisitively into his own face, and singing, singing. Oh! how they sang.