He interrupted the angry conference by bellowing through the bullhorn at them. Then he made signs that he would follow the robbers and indicated that he would like some of them to join him. The robbers could not be too far ahead, even if they had started to work immediately after he left the cave. They would be heavily burdened.

The Silversteins were upset at the turn of events. Von Billmann appeared ready to do whatever Gribardsun wanted. The Englishman told the Silversteins to return to the campsite with the natives. He and the German, and some of the men, if they would agree, would track the robbers.

'But we can't get involved in the quarrels of these people!' Drummond said. 'We don't want to get into the position of having to take sides! Maybe even having to kill their enemies!'

'We'll have to play favorites,' Gribardsun said. 'There's no way of getting away from it. Moreover, the more deeply these people are in our debt, the sooner they'll open up for us. We can't stay neutral.'

'You have no right to shoot those men!' Drummond Silverstein said.

'Who said I would shoot them?' Gribardsun said, staring hard at Silverstein. 'Why don't you ask me what I intend to do instead of making your assumptions?'

'I'm sorry,' Silverstein said. 'Perhaps I'm wrong. But I don't see how you can attempt to take all that meat away from these savages without having to fight them.'

'I have to re-establish our prestige,' the Englishman said. 'Otherwise we'll never be able to know these people inside and out. I've said that twice. Once should be enough.'

He turned away. 'Come on, Robert.'

Four of the tribesmen joined them, among them Thammash and the giant Angrogrim. They set out northward with the Englishman in the lead. He trotted along, looking to both sides for signs. After a mile he saw a track, and a little farther on where a man had spit. Then they entered a morass which held many prints. Gribardsun thought that the party was composed of fourteen men.

They crossed a plain while going toward some hills about a hundred feet high on the horizon. In the distance, to both left and right, were herds of gray-brown mammoths and brownish reindeer. A pack of a dozen hyenas skulked along behind the reindeer. A brown-gray fox sped across the plain after a hare and presently caught it. And then Gribardsun saw their quarry far across the plain. They were all, except for six rearguard men, half covered with parts of the bears.

Gribardsun slowed his pace to allow von Billmann to draw even with him. Von Billmann was panting, though he had gone through the rigorous yearlong physical training prior to the launching. The hunters trotted along, their breaths slightly steaming as the late afternoon turned even colder, the slush splashing over their bare legs. They did not seem in the least hard pressed.

'The two tribes would have come into contact sooner or later anyway,' Gribardsun said. 'One of them probably has only recently moved into this territory. I intend to scare this one away so our subject-study will be left alone.'

'But we want to study their war patterns, too,' von Billmann said.

'That can come later.'

As he ran he was taking films of the men ahead, the area around, and of the men trotting along behind. He ran backward as swiftly as he ran forward while he filmed those behind. By the time they got across the plain, they had lost their quarry, vanished up a pass between two low hills. Here were dead winter grasses with lichen on the rocks and dwarf birches and pines and some beds of saxifrage. A black-and-white badger waddled away from them as they ran into the pass.

Gribardsun supposed that the men they were following had seen them, so he halted his party after it had gone a few yards into the pass. Ahead, the hills grew taller and started to move closer. A brook about five feet wide followed the middle of the pass downward toward the plain, where it suddenly turned and followed the edge of the hills toward the west.

Gribardsun in the lead, his express rifle ready, the party moved slowly up the pass. He expected an ambush, but they got through the pass without incident. They came out onto a small valley which had been formed by a small river. Across the river, up near the top of the hill opposite, was an overhang. This was walled on two sides with piles of stones, and in between were skin tents, tiny at this distance, and a blue haze of smoke under the projecting rock. The robbers were fording the river, and the rearguards were waving at those under the overhang. And, no doubt, they were shouting an alarm.

By the time the invaders reached the bottom of the valley, they could hear the shrilling of bone whistles and flutes and the beat of skin-and-wood drums.

The four tribesmen were looking at each other out of the corners of their eyes and muttering. They were glad to stop at the river when Gribardsun paused to take stock.

'It's not just a matter of a territorial imperative,' von Billmann said. 'We're heavily outnumbered. I'm surprised they've gone this far with us.'

'They know from my signs that I have killed two bears so they must have some faith in my skill, even if they don't know how it was done,' Gribardsun said. 'But I wouldn't be surprised if they ran anyway.'

The ledge under the overhang was alive with men brandishing weapons. Other men, hunters returning, were hastening up the hill to join the defense. The defense, Gribardsun thought, which may soon become an offense. There are only six of us. However, the robbers must believe that one of the invaders had killed two bears with a loud noise. And that meant that the noisemaker was a powerful magician. He would have control over great and mysterious forces. And it was their fear of these forces that Gribardsun depended upon in his plan.

The four natives, however, did not cross the ford. They stood on the bank and gazed apprehensively at the display of spears and dubs on the ledge. Gribardsun turned when he was across the river, shouted at them and made encouraging motions. But they would not follow.

The Englishman took the small Very pistol from his sack, loaded it, and fired it into the air. The explosions and colors silenced the noisy mob on the ledge. Before the flare had parachuted to the ground, the four natives were across the river and standing by Gribardsun's side. They looked pale and grim, but they had evidently decided that it would not be good to offend this witch doctor.

The six advanced slowly up the hillside. Halfway up, they halted. The defenders were behind a row of large boulders along the rim of the ledge, undoubtedly only waiting to shove them over once the intruders were closer.

Gribardsun emptied his express rifle and reloaded with five high-explosive bullets. He aimed at the center boulder on the ledge and fired the bullets, one after the other.

The boulder was a heap of fragments.

The warriors had disappeared.

Gribardsun reloaded with explosive bullets and continued climbing. Before reaching the ledge, however, he stopped and shot three times into the overhang just underneath its edge. Several large pieces of rock fell off. Screams followed the explosions, and warriors, women, and children deserted the site. They fled in two streams down the sides of the ledge and on down the hillside, falling, leaping up again, yelling, shrilling mindlessly.

'I hope they don't hurt themselves,' Gribardsun said.

Their four natives were whooping with joy and slapping each other on the back or the thighs. Then Angrogrim started toward the refugees on their right. He held his spear high, shaking it, and screaming threats at them.

Gribardsun called after him, but the giant continued to run toward the refugees. The Englishman fired into the air, and Angrogrim turned to see what he was doing. Gribardsun gestured fiercely at him to come back. Scowling, the giant obeyed. Gribardsun shook his finger at him and scolded him as if he were a child. Angrogrim looked down at him as if he thought he was very odd. But he did not protest, and when he saw the others continue their climb, he followed them.