Hunt made an impatient gesture.
"He says," he protested, "that you haven't done anything either to Nym or to him to keep them from dying."
Calhoun nodded.
"That's true."
"But—they should die! Nym should die of the Three City sickness! Three City people have always said that we had a sickness too, that did not harm us, but they died of!"
"Which," agreed Calhoun, "is undoubtedly historical fact. However, tempus fugit. Its current value is that of one factor in an isolation syndrome and consequently a complicating factor in the Crusoe health problem here. I've let Nym and Pat go untreated to prove it. I think there's only a sort of mass hypochondria based on strictly accurate tradition, which would be normal."
Hunt shook his head.
"I don't understand," he protested helplessly.
"Some day I'll draw a diagram," Calhoun told him. "It is complicated. Did you check with Pat on what Three City knows about the ribbon in the sky? I suspect it accounts for the terrestrial plants and animals here, indirectly. There wouldn't be an accidental planting of edible nuts and fish and squirrels and pigeons and rabbits and bumblebees! I suspect there was a mistake somewhere. What does Pat say?"
Hunt shrugged his shoulders.
"When I talk to him," added Calhoun, "he doesn't pay attention. He simply gazes at Nym and beams. The man's mad! But you're his father-in-law. He has to be polite to you!"
Hunt sat down abruptly. He rested his spear against a tree and looked over his string of fish. He wasn't used to the abundance of foodstuffs here, and the temperature—Calhoun estimated it at fifty degrees—seemed to him incredibly balmy. Now he thoughtfully separated one fish from the rest and with a certain new skill began to slice away two neatly boneless fillets. Calhoun had showed him the trick the day after a lesson in fish-spearing, which was two days after their arrival.
"Children in Three City," growled Hunt, "are taught the same as in Two City. Men came to this planet to work the mines. There was a Company which sent them, and every so often it sent ships to take what the mines yielded, and to bring things the people wanted. Men lived well and happily. The Company hung the ribbon in the sky so the hotlands could grow food for the men. But presently the mines could not deliver what they made to the ships when they came. The hotlands grew bigger, the glaciers flowed faster, and the pipes between the cities were broken and could not be kept repaired. So the Company said that since the mine produce could no longer be had, it could not send the ships. Those who wanted to move to other worlds would be carried there. Some men went, with their wives and children. However, the grandfathers of our fathers' grandfathers were content here. They had homes and heat and food. They would not go."
Hunt regarded the pinkish brook trout fillet he'd just separated. He bit off a mouthful and chewed, thoughtfully.
"That really tastes better cooked," said Calhoun mildly.
"But it is good this way also," said Hunt. He was grizzled and stocky and somehow possessed dignity which was not to be lost merely by eating raw fish. He waved the remainder of the fillet. "Then the ships ceased to come. Then sickness came. One City had a sickness it gave to people of Two and Three when they visited it. Two City had a sickness it gave to One and Three. Three City . . ." He grunted. "Our children in Two say only Two City people have no sickness. Three City children are taught that only Three City is clean of sickness."
Calhoun said nothing. Murgatroyd tried to gnaw open one of the nuts he'd brought down from the tree. Calhoun took it and another and struck them together. Both cracked. He gave them to Murgatroyd, who ate them with great satisfaction.
Hunt looked up suddenly.
"Pat did not give a Three City sickness to Nym," he observed, "so our thinking was wrong. And Nym has not given a Two City sickness to him. His thinking was wrong."
Calhoun said meditatively, "It's tricky. But sickness can be kept by a carrier, just as you people have believed of other cities. A carrier has a sickness but does not know it. People around the carrier have the sickness on their bodies or their clothing from the carrier. They distribute it. Soon everybody in the city where there is a carrier—" Calhoun had a moment's qualm because he used the word "city." To Hunt the idea conveyed was a bare few hundred people. "Soon everybody is used to the sickness. They are immune. They cannot know it. Somebody from another city can come, and they are not used to the sickness, and they become ill and die."
Hunt considered shrewdly.
"Because the sickness is on clothing? From the carrier?"
Calhoun nodded.
"Different carriers have different sicknesses. So one carrier in One City might have one disease, and all the people in One City became used to it while they were babies, became immune. There could be another carrier with another sickness in Two City. A third in Three City. In each city they were used to their own sickness."
"That is it," said Hunt, nodding. "But why is Pat not dying or Nym? Why do you do nothing to keep them alive?"
"Suppose," said Calhoun, "the carrier of a sickness dies. What happens?"
Hunt bit again, and chewed. Suddenly, he choked. He sputtered, "There is no sickness to spread on the clothing! The people no longer have it to give to strangers who are not used to it! The babies do not get used to it while they are little! There is no longer a One City sickness or a Two City sickness or a Three!"
"There is," said Calhoun, "only a profound belief in them. You had it. Everybody else still has it. The cities are isolated and put out sentries because they believe in what used to be true. People like Nym and Pat run away in the snow and die of it. There is much death because of it. You would have died of it."
Hunt chewed and swallowed. Then he grinned.
"Now what?" His deep voice was quaintly respectful to Calhoun, so much younger than himself. "I like this! We were not fools to believe, because it was true. But we are fools if we still believe, because it is not true anymore. How do we make people understand, Calhoun? You tell me. I can handle people when they are not afraid. I can make them do what I think wise—when they are not afraid. But when they fear . . ."
"When they fear," said Calhoun dryly, "they want a stranger to tell them what to do. You came for me, remember? You are a stranger to One City and Three City. Pat is a stranger to Two City. If the cities become really afraid . . ."
Hunt grunted. He watched Calhoun intently, and Calhoun was peculiarly reminded of the elected president of a highly cultured planet, who had exactly that completely intent way of looking at one.
"Go on!" said Hunt. "How do we frighten them into—this?"
He waved his hand about. Calhoun, his tone very dry indeed, told him. Words would not be enough. Threats would not be enough. Promises would not be enough. Even rabbits and pigeons and squirrels and fish—fish that were frozen like other human food—and piles of edible nuts, would not be enough, by themselves, but . . .
"An isolation syndrome is a neurotic condition, and a Crusoe problem amounts to neurotic hypochondria. You can do it, you and Pat."
Hunt grimaced.
"I hate the cold, now. But I will do it. After all, if I am to have grandchildren there should be other children for them to play with! We will take you back to your ship?"
"You will," said Calhoun. "By the way, what is the name of this planet, anyhow?"
Hunt told him.
Calhoun slipped across the pasture inside the landing grid and examined the ship from the outside. There had been batterings, but the door had not been opened. In the light of the ribbon in the sky he could see, too, that the ground was trampled down but only at a respectful distance. One City was disturbed about the Med Ship, but it did not know what to do. So long as nothing happened from it . . .