“In what way, friend Daneel?”
“Natural radioactivity is also an expression of the weak interaction. A nuclear intensifier that can explode a fusion reactor or a fission reactor can also accelerate natural radioactivity to the point, I presume, of exploding a section of the crust—if enough uranium or thorium is present.”
Giskard stared at Daneel for a period of time without moving or speaking. Then he said softly, “You suggest, then, that it is Dr. Amadiro’s plan to explode Earth’s crust, destroy the planet as an abode of life, and, in this way, ensure the domination of the Galaxy by the Spacers.”
Daneel nodded. “Or, if there is not enough thorium and uranium for mass explosion, the increase of radioactivity may produce excess heat that will alter the climate, and excess radiation that will produce cancer and birth defects, and these will serve the same purpose—if a bit more slowly.”
Giskard said, “This is an appalling possibility. Do you think it can really be brought about?”
“Possibly. It seems to me that for several years now just how many I do not know—humanoid robots from Aurora, such as the would-be-assassin—have been on Earth. They are advanced enough for complex programming and are capable, when needed, of entering the Cities for equipment. They have, it is to be presumed, been setting up nuclear intensifiers in places where the soil is rich in uranium or thorium. Perhaps many intensifiers have been set up over the years. Dr. Amadiro and Dr. Mandamus are here now to oversee the final details and to activate the intensifiers. Presumably, they are arranging matters so that they will have time to escape before the planet is destroyed.”
“In that case,” said Giskard, “it is imperative that the Secretary-General be informed, that Earth’s security forces be mobilized at once, that Dr. Amadiro and Dr. Mandamus be located without delay, and that they be restrained from completing their project.”
Daneel said, “I do not think that can be done—the Secretary-General is very likely to refuse to believe us, thanks to the widespread mystical belief in the inviolability of the planet. You have referred to that as something that would work against humanity and I suspect that is just what it will do in this case. If his belief in the unique position of Earth is challenged, he will refuse to allow his conviction, however irrational, to be shaken and he will seek refuge by refusing to believe us.
“Then, too, even if he believed us, any preparation for counter-measures would have to go through the governmental bureaucracy and, no matter how that process was speeded, it would take far too long to serve its purpose.
“Not only that but, even if we could imagine the full resources of Earth mobilized at once, I do not think Earthpeople are adapted to locate the presence of two human beings in an enormous wilderness. The Earthpeople have lived in the Cities for many scores of decades and almost never venture beyond the City confines. I remember that well from the occasion of my first case with Elijah Baley here on Earth. And even if Earthpeople could force themselves to tramp the open spaces, they are not likely to come across the two human beings soon enough to save the situation except by the most incredible of coincidences—and that is something we cannot count upon.”
Giskard said, “Settlers could easily form a search party. They are not afraid of open environments or of strange ones.”
“But they would be as firmly convinced in the planet’s inviolability as Earthpeople are, just as insistent on refusing to believe us, and just as unlikely to find the two human beings quickly enough to save the situation—even if they should believe us.”
“What of Earth’s robots, then?” said Giskard. “They swarm in the spaces between the Cities. Some should already be aware of human beings in their midst. They should be questioned.”
Daneel said, “The human beings in their midst are expert roboticists. They would not have failed to see to it that any robots in their vicinity remain unaware of their presence. Nor, for this same reason, need they fear danger from any robots who might be part of a searching party. The party will be ordered to depart and forget. To make it worse, Earth’s robots are comparatively simple models, designed for very little more than for specific tasks in growing crops, herding animals, and operating mines. They cannot easily be adapted to such a general purpose as conducting a meaningful search.”
Giskard said, “You have eliminated every possible action, friend Daneel? Does anything remain?”
Daneel said, “We must find the two human beings ourselves and we must stop them—and we must do it now.”
“Do you know where they are, friend Daneel?”
“I do not, friend Giskard.”
“Then if it seems unlikely that an elaborate search party composed of many, many Earthpeople, or Settlers, or robots, or, I presume, all three, could succeed in finding their location in time except by the most marvelous of coincidences, how can we two do so?”
“I do not know, friend Giskard, but we must.”
And Giskard said, in a voice that seemed to have an edge of harshness in its choice of words, “Necessity is not enough, friend Daneel. You have come a long way. You have worked out the existence of a crisis and, bit by bit, you have worked out its nature. And none of it serves. Here we remain, as helpless as ever to do anything about it.”
Daneel said, “There remains one chance—a farfetched one, an all-but-useless one—but we have no choice except to try. Out of Amadiro’s fear of you, he sent an assassin robot to destroy you and that may turn out to have been his mistake.”
“And if that all-but-useless chance fails, friend Daneel?”
Daneel looked calmly at Giskard. “Then we are helpless, and Earth will be destroyed, and human history will dwindle to an eventual end.”
18. THE ZEROTH LAW
92
Kelden Amadiro was not happy. The surface gravity of Earth was a trifle too high for his liking,—the atmosphere a trifle too dense, the sound and the odor of the outdoors subtly and annoyingly different from that on Aurora, and there was no indoors that could make any pretense of being civilized.
The robots had built shelters of a sort. There were ample food supplies and there were makeshift privies that were functionally adequate but offensively inadequate in every other way.
Worst of all, though the morning was pleasant enough, it was a clear day and Earth’s too bright sun was rising. Soon the temperature would be too high, the air would be too damp, and the biting insects would appear. Amadiro had not understood, at first, why there should be small itching swellings on his arms till Mandamus explained.
Now he mumbled, as he scratched, “Dreadful! They might carry infections.”
“I believe,” said Mandamus with apparent indifference, “that they sometimes do. It isn’t likely, however. I have lotions to relieve the discomfort and we can bum certain substances that the insects find offensive, although I find the odors offensive, too.”
“Burn them,” said Amadiro.
Mandamus continued, without changing tone, “And I don’t want to do anything, however trifling—an odor, a bit of smoke—that would increase the chance of our being detected.”
Amadiro eyed him suspiciously. “You have said, over and over, that this region is never visited by either Earthpeople or their field robots.”
“That’s right, but it’s not a mathematical proposition. It’s a sociological observation and there is always the possibility of exceptions to such observations.”