Gribardsun denied the requests. He said that Dubhab had been allowed to handle the guns only to test his reaction to them. It was thought wiser not to let anybody else try them, and, furthermore, Dubhab would be denied their use from now on. Dubhab smiled and said that whatever the strangers wished was his wish also. But Gribardsun wondered what was behind that smile and the big blue eyes. Dubhab continued to praise the charms of his older daughter Neliska and to say openly that Gribardsun should take her as a mate. There was no doubt that Dubhab hoped to profit from his position as father-in-law.

Neliska said that she would be honored to become Gribardsun's mate. Gribardsun said that Neliska was very desirable, but he had no plans for taking a mate for some time.

Dubhab then suggested, when he was alone with Gribardsun, that the Englishman take Neliska without benefit of the marriage ceremony. A great spirit such as Gribardsun would not be bound by the conventions that bound mere human beings. And Neliska would be happy to bear a child to the great spirit.

Gribardsun told Dubhab to shut up about this business or he would turn him in to the elders. And the elders might consider exiling Dubhab for even thinking of breaking the customs of the tribe.

Dubhab turned gray at this remark. Like all preliterates, he dreaded more than anything being cut off from his tribe. The mere suggestion turned his bones to ice.

Yet it was only two days later that he remarked to Gribardsun that a man equipped with firearms would be in a position to change the customs of the tribe.

'That man is not only the archetypal con man,' Rachel said. 'He is the Ur-Napoleon, the pre-Hitler type.'

The Basic-Napoleon-c.u.m-Confidence-Man, however, was begging Gribardsun a week later to pull one of his teeth. He was suddenly suffering excruciating pain from an impacted wisdom tooth. The Englishman used his tiny sonic machine to take pictures, and found that the tooth was deeply abscessed. Moreover, the other three teeth were rotten and would have to come out. And all three would fall apart during extractions; they would probably have to be dug out.

Gribardsun explained to Dubhab what he had to do. And he also made sure that Dubhab understood that he now owed his life to Gribardsun. If the teeth were left to natural processes, or to the brutal and inadequate oral surgery of Glamug, Dubhab would die. Gribardsun took such pains to establish Dubhab's debt of grat.i.tude because he wanted to insure bis behavior in the future.

The operation was a success, and the patient did not die, although there were times when he said he would almost rather be dead.

The entire tribe witnessed the operation. The most remarkable thing to them was that Dubhab slept through it.

Glamug asked for, and received, Dubhab's teeth, which were mainly fragments. He put them into a little skin pouch, waved his one-eyed baton de commandement over it while he chanted protective phrases, and then buried them secretly on the side of a mountain under a rock. No one would be able to use them in magical rites against Dubhab. But Gribardsun suspected that Glamug kept several small pieces of a wisdom tooth in case Dubhab ever became hostile to him.

Then again, perhaps Glamug was innocent. By custom, Dubhab could kill him and go free if he caught Glamug using any parts of his body - nails, teeth, hairs, saliva - against him.

Dubhab recovered amazingly fast, helped by the antibiotics and Gribardsun's care. Three days later, the tribe packed their tents and belongings and moved southward again. Gribardsun marched at the head. Behind him were his three colleagues. Behind them was Glamug, shaking his baton or the pebbles in a gourd at the end of a stick. Then Thammash the chief and Angrogrim the greatest warrior. And then Wazwim, the singer, who was in one sense as much a witch doctor as Glamug, since most songs were sung for magical purposes. After Wazwim was Shivkaet, the carver and the painter, who did much of his work under the supervision of Glamug. His products were mostly used for magical purposes, too. Then came Dubhab, who had lost bis smile and seemed much withdrawn and grouchy. After him came other males according to their unstated but well-recognized rank in their society. And then the women and children according to their ranks.

The flanks and the rear were guarded by the lesser warriors and juveniles who had not been 'blooded' as yet. The 'blooding,' in most cases, would consist of a symbolic conflict during a ceremony. There was very little actual fighting between tribes. The hostilities with the Wotagrub had taken more casualties in a few minutes than even the oldest man, Kwakamg, remembered having taken place in his whole life. Occasionally a lone hunter or perhaps a couple of hunters had accidentally run into alien hunters and there had been some exchange of spears or rocks. And now and then a man had been killed or a woman or child ambushed. But these incidents were infrequent. In fact, several days later, while Kwakamg was recounting the largest battle he remembered, which had taken place during the Winter of the Red Snow, Kwakamg dropped dead. Whether it was the excitement of the memory coupled with an age-weakened heart, or whether his heart would have given way at that moment anyway, no one knew. Gribardsun dissected him because he was eager to get data on the incidence of heart disease among the Magdalenians. Kwakamg was white-haired and wrinkled and had had a slight palsy. But the dissection convinced Gribardsun that Kwakamg was probably not more than sixty. His heart was that of an eighty-year-old man. At some time in Kwakamg's life he had had rheumatic fever. He had also had rheumatism, smallpox, and had lost about twelve teeth. But six had been knocked out during an encounter with a cave bear. The others had been rotten, and Glamug had pulled them out without much trouble for himself and only great pain for Kwakamg.

Two days later, Gribardsun delivered the baby of Meena, a sixteen-year-old woman, wife of Shimkoobt. Both the mother and baby would have died if Gribardsun had not been there, since he was forced to take the infant by caesarian.

Glamug told him that caesarians were not unknown. But almost always the mother died and the baby was lucky to survive.

Gribardsun recorded this data. And he wondered when the first caesarian had been performed. No one would probably ever know, since no time machine could yet go deeper into the past.

'So you have affected the future materially,' Rachel said. 'Who knows? If it weren't for you, many of us twenty-first centurians wouldn't exist. Perhaps even you wouldn't exist.'

'Speculation is interesting but essentially useless,' the Englishman said. 'I have changed nothing. Before I was born, everything I had done in the past had been done.'

'Let's not get involved in any more of these time paradoxes,' Rachel said. 'I always end up with a dizzy feeling, and slight sickness at the stomach, after trying to untangle the metaphysics and supermechanics of Time!'

'Time is something man will never comprehend,' Gribardsun said. 'Partly because Time is outside man. Man is, of course, partly in Time, but there are elements of Time that are completely exterior to him. He can't even see those elements and never will because they can't be put under the microscope or telescope or be detected by radiation-sensitive equipment.'

He and Rachel were walking down the slope of a valley. He had three hares on a rope slung over his shoulder. The beasts had been caught in traps, and the two were headed for another trap they had set two days before. The snow covered the ground by about two feet. Tall green snow-laden firs and pines rose on every side, but presently they came to a clear stretch. A dozen or so large boulders were scattered around the clearing. Their breaths steamed, and above them a large eagle swung, running its stiff-winged shadow ahead of them.

Gribardsun had not wished to be alone with Rachel, but she had asked if she could accompany him. He disliked saying no, because she had behaved toward him for months as if he were just another scientist. Apparently she and Drummond were now living with no more than the friction most married couples experienced.

'The thing to do is to enjoy Time as much as you can,' he said. 'Live as the beasts do. From day to day. If you think of the end of Time, that is, of your own death, accept it as part of Time. You can do nothing about it, so why worry about it??

'But you, you're the exception -' Rachel said, and then she stopped. Her eyes were wide and her mouth open. Her hand was at her throat, as if she would choke off her words.

'I am?'he said.'Why?'

'I mean,' Rachel said, 'that you, or anybody, might be the exception. That's what I meant. What if somebody found a means to extend his life span for a very long time, and then...?'

'And then what?' Gribardsun said. He had stopped and was looking down at her with large and bright gray eyes.

Rachel shivered, and yet she could not have been cold. The sun was warm and she was covered and hooded with the thin but very warm thermicron material.

'I was just speculating,' she said. 'Surely, sometime in man's history, somebody must have stumbled across an elixir of a sort, something which kept a man young for a very long time. Don't you think that's possible?'

'It's possible,' he said, smiling. She shivered again. 'When I was a young man, I heard stories among the natives of Africa about witch doctors who had invented an elixir of youth. It was also supposed to confer immunity to all diseases. But mankind wishes for such an elixir and so he makes up stories to the effect that such a thing does exist.'

'Well,' Rachel said, 'just suppose such a person as I postulated did exist? Wouldn't you think he'd become very lonely? He'd see those he loved get old and ugly and die. And his own sons, and his grandsons, would age and die. And he'd be bound to fall in love many times, and raise children, and each time his wife would inevitably die.'

She stopped, licked her lips, and moved closer to him. Her chin was lifted high so she could look up into his eyes.

'Unless,' she said, 'this man knew how to make the elixir. Then he could keep his wife and his children young also. Of course, he'd have to swear them to secrecy, and that might be such a dangerous thing that he would hesitate. It would be difficult for most people to keep such a secret to themselves. Most people, I say.'

'But not for you?' he said, smiling.

'Yes, but not for me!' she said.

'I hope you find someone who has the elixir,' he said. 'If he should exist. Which he won't in this era, of course. Although you never know. Perhaps some plant exists which could provide the basis of an elixir. And then that plant will become extinct. But the elixir only has to be used once. The effect of the elixir might be permanent, relatively speaking.'

'Maybe I shouldn't be saying anything,' she said. 'But when you were gone, visiting the Wotagrub, Drummond and Robert and I had a long talk about you. We concluded that there was something very strange about your being chosen as a member of this expedition. And we agreed that there was something strange about your background. Every once in a while you let slip some peculiar remarks that can only be accounted for by your having lived a long long time, far longer...'

Gribardsun had not lost his smile. He said, 'I wonder if your displacement in time hasn't resulted in some sort of shock. Shall we call it temporal shock? Or the temporal syndrome? A human being can't be catapulted backward in time, to an age so alien in nature, so savage, and so very far away from his own world, without suffering a neurosis or perhaps even psychosis.'

'If that were true, then you'd be just as much in shock as we,' she said. 'But you're getting me off the track. I was...'

She stopped. He had looked up over her shoulder at something far up the hill. He had stiffened.

'What's wrong?' she said. She turned around and looked up the steep slope. But she could see only the sun-bright snow and the green and white firs and pines, the eagle; and several gray shadowy shapes - wolves - far to the right near the top of a ridge. But he was looking to the left.

'I thought I saw something moving up there,' he said. 'Among the trees.'

She moved against him and put her arms around him without thinking about it. It was the expression of her long-repressed desire, and he knew it at once. She realized it several seconds later, but by then it was too late. She did not withdraw; she stood on her toes and kissed him.

The bullet tore the fabric of their solitude within an inch of their ears - or so it seemed - and then the report of the rifle reached them.

Gribardsun shoved her sprawling into the snow and dived after her.

Rachel had uttered a m.u.f.fled scream. Now she raised her head, looking like a snow maiden. The powdery stuff was over her face and ringing her large blue eyes.

'It's Drummond!' she said. 'But why would he do it? How could he? It's not like him! He's not violent! He's not a murderer!'

Gribardsun may have considered that her husband was the most probable suspect. But he said, 'Let's not accuse anybody until we know for certain who...'