"Paras are ... beings that once were sane men. They aren't sane any longer. Perhaps they aren't men any longer. Something has happened to them. If you'd landed a day or two later, you couldn't have landed at all. We normals had planned to blow up the landing grid so no other ship could land and be lifted off again to spread the ... contagion to other worlds. If it is a contagion." "Smashing the landing grid," said Calhoun practically, "may be all right as a last resort. But surely there are other things to be tried first!" Then he stopped. The ground car in which he rode had reached the spaceport gate. Three other ground cars waited there. One swung into motion ahead of them. The other two took up positions behind. A caravan of four cars, each bristling with blast weapons, swept along the wide highway which began here at the spaceport and stretched straight across level ground toward the city whose towers showed on the horizon. The other cars formed a guard for Calhoun. He'd needed protection before, and he might need it again. "Medically," he said to the Minister for Health, "I take it that a para is the human victim of some condition which makes him act insanely. That is pretty vague. You say it hasn't been controlled. That leaves everything very vague indeed. How widely spread is it? Geographically, I mean." "Paras have appeared," said the Minister for Health, "at every place on Tallien Three where there are men." "It's epidemic, then," said Calhoun professionally. "You might call it pandemic. How many cases?" "We guess at thirty per cent of the population--so far," said the Minister for Health, hopelessly. "But every day the total goes up." He added: "Dr. Lett has some hope for a vaccine, but it will be too late for most." Calhoun frowned. With reasonably modern medical techniques, almost any sort of infection should be stopped long before there were as many cases as that! "When did it start? How long has it been running?" "The first paras were examined six months ago," said the Health Minister. "It was thought to be a disease. Our best physicians examined them. They couldn't agree on a cause, they couldn't find a germ or a virus...." "Symptoms?" asked Calhoun crisply. "Dr. Lett phrased them in medical terms," said the Minister for Health. "The condition begins with a period of great irritability or depression. The depression is so great that suicide is not infrequent. If that doesn't happen, there's a period of suspiciousness and secretiveness--strongly suggestive of paranoia. Then there's a craving for--unusual food. When it becomes uncontrollable, the patient is mad!" * * * * * The ground cars sped toward the city. A second group of vehicles appeared, waiting. As the four-car caravan swept up to them, one swung in front of the car in which Calhoun and Murgatroyd rode. The others fell into line to the rear. It began to look like a respectable fighting force.