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.... He was working the combination lock-door when something hopped, low-down and near him. He jumped, and Murgatroyd said, "_Chee?_" Then Calhoun realized what had startled him. He finished the unlocking of the port. He went in and closed the port behind him. The air inside seemed curiously dead, after so long a time outside. He flipped on the outside microphones and heard tiny patterings. He heard mildly resentful cooings. He grinned. When morning came, the people of One City would find their pastureland inhabited by small snowshoe rabbits and small and bush-tailed squirrels and fluttering pigeons. They would react as Two City and Three City had already done--with panic. And panic would inevitably call up the notion of the most-feared thing in their lives. Sickness. The most-feared thing is always a rare thing, of course. One cannot fear a frequent thing, because one either dies of it or comes to take it for granted. Fear is always of the rare or nonexistent. One City would be filled with fear of sickness. And sickness would come. Hunt would call them, presently, on a walkie-talkie communicator. He would express deep concern because--so he'd say--new domestic animals intended for Two City had been dumped on One City pastureland. He'd add that they were highly infective, and Two City was already inescapably doomed to an epidemic which would begin with severe headaches, and would continue with cramps and extreme nervous agitation. And he would say that Calhoun had left medicines at Two City with which that sickness and all others could be cured, and if the sickness described should appear in One City--why--its victims could be cured if they traveled to Two City. The sickness would appear. Inevitably. There was no longer sickness in the three communities. Arctic colonies, never visited by people from reservoirs of infection, become magnificently healthy by the operation of purely natural causes. But an isolation syndrome.... The people of One City would presently travel, groaning, to Two City. Their suffering would be real. They would dread the breaking of their isolation. But they'd dread sickness--even sickness they only imagined--still more. And when they reached Two City they would find themselves tended by Three City members, and they would be appalled and terrified. But mumbo-jumbo medication by Hunt and Pat--and Nym for the women--would reassure them. A Crusoe condition requires heroic treatment. This was it. * * * * *