There was, however, one undeniable realistic reason why one hundred years was the limit for this group of people. The energy needed to fill the grails, to run the tower and to resurrect the dead, was derived from the heat from this planet's molten nickel-iron core. The available energy was enormous, but so was the consumption of it. The Ethicals might have figured out that a hundred years for this group, people who had lived from 100,000 b.c. through a.d. 1983, and a hundred years for the next group, those who had lived after a.d. 1983, would eat up almost all the tappable energy. With all the heat that the thermionic converters drew, two hundred years' withdrawal would cool off the core to the point where it could no longer supply the requirements.

Loga, the Ethical, had never mentioned this energy limitation. He must have known it, and it must have caused him anguish and guilt. Nur, having thought of this factor, had asked the Computer to give him the computation for the energy needed for the two projects. And the answer had been what Nur had expected. Yes, even the core of this planet, slightly larger than Earth's, would lose its white-hot glow and become red and dim within two centuries.

Loga's parents, siblings, and cousins were still in the River-valley. Every one of them had been killed at least once, and none had Gone On. Loga had interfered with the project and gotten rid of his fellow Ethicals and the Ethical Agents so that his family might live longer than the time allotted to them. And, Loga hoped, attain that level where they could Go On.

That did not mean, however, that this project, the first, would not be terminated when the hundred years were up. He could salvage his loved ones by making sure that their body-recordings would not be erased and their wathans released to float for as long as the universe lasted or perhaps longer. He could end the first group and start the next group on schedule. The slight deviation in the procedure would be that his family would continue to live in The Valley. They would be part of the next group and thus get an extra century.

If that were so, why had Loga not just arranged that the Computer would not report that certain persons who should have been disposed of were still living? Loga had been able to fix it so that the Computer had operated illegally in far more noticeable matters.

Probably, Loga had not wanted to take the chance that he could get by with the minor matter—major, from his viewpoint. He had to assure his complete control, even if trying to do this made the risks far greater. He knew that a year or two before the end of this project, a spaceship would arrive from the Gardenworld. It would hold a crew of Ethicals and the body-records of the people for the second project. Loga had to insure that the newcomers would not interfere with him. He had set things up so that the newcomers would be seized or killed when they unsuspectingly got off the ship in the hangar.

Unfortunately, somebody had gotten to Loga, killed him and erased his body-recording.

All evidence pointed to the Mongolian female agent who had been killed by Nur. But Nur had very little evidence to go by. He had no idea how she had gotten into the tower, what her role was or what it had been intended to be, or, even, whether she was still not hiding some place in the tower.

Nur and his companions were supposed to have worked on this mystery until it was solved. However, everybody except himself seemed to have neglected it. They were too occupied with the power and the pleasures the tower gave them. Undoubtedly, they had intended to try to solve the enigma, but they had no idea of how much time had passed.

Nur wondered if it would do any good to call this neglect to their attention. He had gotten nowhere in his efforts to clear matters up via the Computer. Why would they do any better?

Yet it was Alice Hargreaves who had thought of the way to trick the Computer shortly after they had gotten into the magic labyrinth, the tower that was also the Computer. Not he, Nur, not any of the others. He knew, however, from observing them, that they just did not think that solving the mystery was urgent. In fact, nothing seemed urgent to them now except enjoying the treasures of the Computer. And they were in no hurry to get all of those.

They were wrong in thinking that. Nur could see another crisis speeding toward them. Li Po had launched that when he had resurrected people without much thought about the effects. Turpin had then raised many whom he had known on Earth and some he had first known in The Valley. These, in turn, had raised those they wanted to have with them. And so on. Turpinville was already crowded; Turpin was going to oust any more newcomers. They would not care; they would just move into one of the unoccupied worlds or into an apartment suite. And there they would continue the populating.

Most of the people brought in had never even heard of computers, not even those primitive and limited ones of Earth technology. Here they were introduced to a machine that made them, in a sense, demigods. But, being human, many of them would misuse the power through accident or design. Williams, for instance, had raised those involved in the Ripper murders just as a rather malicious joke. Nur could not see that there was any harm in that except that Netley might abuse his power. The others seemed to be decent people. Gull had become born again, as the curious Christian phraseology put it, and the three women were not vicious or power-hungry. The men that they had resurrected to be their companions might be another matter, however. And many of those brought to Turpinville had not changed much since they had been on Earth. A town full of those who had been on Earth pimps, whores, drug sellers, bullies and killers held much danger. Especially when they could operate the Computer.

What Nur had tried but failed to impress on his companions was that the Computer was a genie let out of a bottle or an afreet that had been released from the constraints of Solomon's Seal. Or, as Frigate had put it, a Frankenstein's monster with an unlimited credit card. One person using these powers might suddenly find that another was using them against him or her. The full potentialities of the Computer were still unknown. To use it safely, you had to learn everything it could do, and that would take a long, long time.

For instance, Burton, while watching those in the Ripper case, had not considered that he was being watched while watching. If he had foreseen the possibilities, he would have put an inhibit on anyone spying on him. Now that he knew it could be done, he had ordered the Computer to insure his privacy in his operation of it. But it was rather late for that. Five people, one of whom, Netley, might be a danger to everybody else, had been brought in. Moreover, if Williams had thought of it, he could have told the Computer to override Burton's privacy instructions and not tell Burton about it.

Whoever got to the Computer first could override the latecomers.

Only one who learned the list of all that the Computer could do could protect himself. And the others. Even then, he might be too late. Another might have already put in commands giving himself control channels that he had made sure would be denied to others.

Nur intended to go through the list of potentialities, learn them by heart, and then see to it that the Computer would deny control to anyone who could misuse certain powers. That would, of course, give him the greatest power of anyone in the tower. But he knew that he would not use it for evil purposes.

For the moment, though, he had other things to do. His allotted work hours for the day were over. He must go now and have dinner with the woman he had raised, his wife on Earth, a woman whom he had not seen much there because he had been traveling in his quest for knowledge and the Truth. He owed her much, and now he could repay her.