"My experience," said Calhoun, "has been mostly with diseases that one either recovers from or dies of. A disease whose victims organize to steal weather rockets and to use them to destroy a ship—only they failed—and who carry on with an assassination attempt ... that doesn't sound like a disease! A disease has no purpose of its own. They had a purpose—as if they obeyed one of their number."
The Minister for Health said uneasily:
"It's been suggested—that something out of the jungle causes what's happened. On other planets there are creatures who drink blood without waking their victims. There are reptiles who sting men. There are even insects which sting men and inject diseases. Something like that seems to have come out of the jungle. While men sleep—something happens to them! They turn into paras. Something native to this world must be responsible. The planet did not welcome us. There's not a native plant or beast that is useful to us! We have to culture soil-bacteria so Earth-type plants can grow here! We don't begin to know all the creatures of the jungle! If something comes out and makes men paras without their knowledge——"
Calhoun said mildly:
"It would seem that such things could be discovered."
The Health Minister said bitterly:
"Not this thing! It is intelligent! It hides! It acts as if on a plan to destroy us! Why ... there was a young doctor who said he'd cured a para! But we found him and the former para dead when we went to check his claim! Things from the jungle had killed them! They think! They know! They understand! They're rational, and like devils——"
A third group of ground cars appeared ahead, waiting. Like the others, they were filled with men holding blast rifles. They joined the procession—the rushing, never-pausing group of cars from the spaceport. The highway had obviously been patrolled against a possible ambush or road block. The augmented combat group went on.
"As a medical man," said Calhoun carefully, "I question the existence of a local, nonhuman rational creature. Creatures develop or adapt to fit their environment. They change or develop to fit into some niche, some special place in the ecological system which is their environment. If there is no niche and no room for a specific creature in an environment, there is no such creature there! And there cannot be a place in any environment for a creature which will change it. It would be a contradiction in terms! We rational humans change the worlds we occupy! Any rational creature will! So a rational animal is as nearly impossible as any creature can be. It's true that we've happened, but—another rational race? Oh, no!"