Flocks of birds and small winged mammals passed him. They were headed for the planet, which meant that the moon's shape-change wasn't far off. The three had left just in time.

Briefly, his craft went through a layer of winged and threaded seeds, soaring, whirling.

The flames ate up the wood, and the supply began to look rather short to Kickaha. The only consolation was that as the fuel burned, it relieved the balloon of more weight. Hence, the aerostat was lighter and ascended even more swiftly.

At an estimated fifteen miles altitude, Kickaha guessed that he had enough to go another five miles.

McKay's balloon was drifting away from the others. Anana's was about a half a mile from Kickaha's, but it seemed to have stopped moving away from it.

At twenty miles-estimated, of course-Kickaha threw the last stick of wood onto the fire. When it had burned, he scraped the hot ashes over the side, leewards, and then pushed the earth after it. After which he closed the funnel of rawhide which had acted as a deflector. This would help keep the hot air from cooling off so fast.

His work done for the moment, he leaned against the side of the basket. The balloon would quickly begin to fall. If it did, he would have to use the parawing to glide back to the moon. The only chance of survival then would be his good luck in being on the upper side after the shape-change.

Suddenly, he was surrounded by warm air. Grinning, he waved at Anana, though he didn't expect her to see him. The rapid change in the air temperature must mean that the balloon had reached what Urthona called the gravity interface. Here the energy of the counterrepulsive force dissipated or "leaked" somewhat. And the rising current of air would keep the aerostats aloft for a while. He hoped that they would be bouyed long enough.

As the heat became stronger, he untied the funnnel, and he cut it away with his knife. The situation was uncertain. Actually, the balloon was falling, but the hot air was pushing it upwards faster than it descended. A certain amount was entering the neck opening as the hotter air within the bag I slowly cooled. But the bag was beginning to collapse. It would probably not completely deflate. Nevertheless, it would fall.

Since the balloon was not moving at the speed of the wind now, Kickaha felt it. When the descent became rapid enough, he would hear the wind whistling through the suspension ropes. He didn't want to hear that.

The floor of the car began to tilt slowly. He glanced at Anana's balloon. Yes, her car was swinging slowly upwards, and the gasbag was also beginning to revolve.

They had reached the zone of turnover. He'd have to act swiftly, no hesitations, no fumbles.

Some birds, looking confused but determined, flapped by.

He scrambled up the ropes and onto the net, and as he did so the air became even hotter. It seemed to him that it had risen from a estimated 100° Fahrenheit to 130° within sixty seconds. Sweat ran into his eyes as he reached the parawing and began cutting the cords that bound it to the net. The envelope was hot but not enough to singe his hands and feet. He brushed the sweat away and severed the cords binding the harness and began working his way into it. It wasn't easy to do this, since he had to keep one foot and hand at all times on the net ropes. Several times his foot slipped, but he managed to get it back between the rope and skin of the envelope.

He looked around. While he'd been working, the turnover had been completed. The great curve of the planet was directly below him; the smaller curve of the moon, above.

McKay's balloon was lost in the red sky. Anana wasn't in sight, which meant that she too was on the side of the balloon and trying to get into the harness.

Suddenly, the air was cooler. And he was even more aware of the wind. The balloon, its bag shrinking with heart-stopping speed, was headed for the ground.

The harness tied, the straps between his legs, he cut the cord which held the nose of the wing to the net. There was one more to sever. This held the back end, that pointing downward, to the net. Anana had cautioned him many times to be sure to cut the connection at the top before he cut that at the bottom. Otherwise, the uprushing air would catch the wing on its undersurface. And the wing would rise, though still attached at its nose to the balloon. He'd be swung out at the end of the shrouds and be left dangling. The wing would flatten its upper surface against the bag, pushed by the increasingly powerful wind.

He might find it impossible to get back to the ropes and climb up to the wing and make the final cut.

"Of course," Anana had said, "you do have a long time. It'll be eighty miles to the ground, and you might work wonders during that lengthy trip. But I wouldn't bet on it."

Kickaha climbed down the ropes to the rear end of the wing, grabbed the knot which connected the end to the net, and cut with the knife in his other hand. Immediately, with a quickness which took his breath away, he was yanked upwards. The envelope shot by him, and he was swinging at the end of the shrouds. The straps cut into his thighs.

He pulled on the control cords to depress the nose of the wing. And he was descending in a fast glide. Or, to put it another way, he was falling relatively slowly.

Where was Anana? For a minute or so, she seemed to be lost in the reddish sky. Then he located a minute object, but he couldn't be sure whether it was she or a lone bird. It was below him to his left. He banked, and he glided towards her or it. An immeasurable time passed. Then the dot became larger and after a while it shaped itself into the top of a parawing.

Using the control shrouds to slip air out of the wing, he fell faster and presently was at the same level as Anana. When she saw him she banked. After some jockeying around, they were within twenty feet of each other.

He yelled, "You O.K.?"

She shouted, "Yes!"

"Did you see McKay?"

She shook her head.

Two hours later, he spotted a large bird-shaped object at an estimated two thousand feet below him. Either it was McKay or a roc. But a long squinting at it convinced him that it must be a bird. In any event, it was descending rapidly, and if it continued its angle, it would reach the ground far away from them.

If it was McKay, he would just have to take care of himself. Neither he, Kickaha, nor Anana owed him anything.

A few seconds later he forgot about McKay. The first of a mass migration from the moon passed him. These were large geese-type birds which must have numbered in the millions. After a while they became mixed with other birds, large and small. The air around him was dark with bodies, and the beat of wings, honks, caws, trills, and whistles was clamorous.

Their wings shot through a craggle of cranes which split, one body flapping to the right, one to the left. Kickaha supposed that they'd been frightened by the machines, but a moment later he wasn't sure. Perhaps it was the appearance of an armada of rocs which had scared them.

These airplane-sized avians now accompanied them as if they were a flying escort. The nearest to Anana veered over and glared at her with one cold yellow eye. When it got too close, she screamed at it and gestured with her knife. Whether or not she had frightened it, it pulled away. Kickaha sighed with relief. If one of those giants attacked, its victim would be helpless.

However, the huge birds must have had other things on their minds. They maintained the same altitude while the parawings continued descending. After a while the birds were only specks far above and ahead.

Anana had told him that this would not be the longest trip he'd ever taken, but it would be the most painful. And it would seem to be the longest. She'd detailed what would happen to them and what they must do. He'd listened, and he'd not liked what he heard. But his imagination fallen short of the reality by a mile.