"I suppose," said Calhoun, "there's a lot of concern about the—epidemic. The planetary health department asked for me."
"Yes, sir! It's real bad! Started three months ago. There were half a dozen cases of pneumonia. Nobody thought much about it. They were treated, and stopped having pneumonia, but they weren't well. They had something else, not the same thing, either. There was typhoid and meningitis and so on. This is what the newscasts say. Then other cases turned up. A child would have measles, and it would turn to tetanus, and that to pneumonia, and that to scarlet fever. . . . It couldn't happen, the doctors said, but it was happening! The hospitals filled up. More came in all the time, and none of them could leave. They could keep most of the cases alive, but they had to cure 'em of something else all the time. They had to turn schools and churches into hospitals. One person in ten is sick already. More are taken down every minute. Presently, there won't be doctors enough to diagnose the diseases patients contract continually. They figure that a quarter of the whole population will be down inside of two weeks more, and then they'll start dying faster than they do now, because there won't be enough well people to take care of 'em. They figure there won't be anybody on his feet in a month and a half from now and that'll be the end for everybody."
Calhoun clamped his jaws together.
"They've stopped giving it out," said the grid operator. He added professionally, "I've got you coming down at four hundred feet a second, but I'm going to pull a lot harder! You're needed down here in a hurry! I'll put on the brakes at a thousand miles, and you'll touch ground like a feather."
Calhoun ground his teeth. Strictly speaking, he should discuss the plague only with qualified medical men. But the public attitude toward a disease has to be considered in its treatment. This, however, was plainly not a disease. A given bacterium or virus can produce one disease only. Its activity may vary in virulence, but not in kind. Viruses do not change to bacteria. Cocci do not change to spirochetes. Each pathogenic organism that exists remains itself. It may change in viciousness, but never in form. The plague as described could not be a plague! It could not be!
Immediately one ceased to think of it as a natural plague; immediately one considered it artificial, it made sense. It tended to spread toward a total, cent-percent matching of number of cases to the number of people on the planet. Normal pestilences do not. It was planned that a fake Med Ship man should arrive at a certain time and end it. This would be absurd if the plague were a natural one. It was the third of its kind, and the first two had killed tormals—which pestilences could not—and in each case large sums of money had disappeared.
"Doctor Kelo, sir," said the grid operator, said he was sure that if a Med Ship man could get here with his—what's that little creature? A tormal? Once a Med Ship man got here with his tormal, the plague was as good as licked." He stopped and listened. "Doctor Kelo must be here now. There's a copter landing outside."
Then the grid man said with a rather twisted grin, "I tell you, everybody's glad you're here! I've got a wife and kids. They haven't got the plague yet, but . . ."
He stood up. He said joyously, "Doctor Kelo! Here he is! Right here on the screen! We've been talkin'. He's comin' down fast, and I'll have him aground in a hurry!"
A voice said, "Ah, yes! I am most pleased. Thank you for notifying me."
Then a new figure appeared on the vision screen. It was dignified. It was bearded. It was imposing in the manner of the most calmly confident of medical men. One could not look at Doctor Kelo without feeling confidence in him. He seemed benign. He beamed at the grid man and turned to the vision screen.
He saw Calhoun. Calhoun regarded him grimly. Doctor Kelo stared at him. Calhoun was not the man who'd been put aboard the Med Ship at first breakout point. He wasn't the man who'd handled the Castor IV epidemic, or the one before that. He wasn't the man who was supposed to have been killed when a Med Ship blew up in the Castor IV spaceport. He wasn't . . .
"How do you do?" said Calhoun evenly. "I gather we are to work together—again, Doctor Kelo."
Doctor Kelo's mouth opened, and shut. His face went gray. He made an inarticulate sound. He stared at Calhoun in absolute stupefaction. Murgatroyd squirmed past Calhoun's body to look into the communicator screen. He saw a man, and to Murgatroyd that meant that shortly he would be aground among people who admired him adoringly and would therefore stuff him with all the things he liked to eat and drink.
"Chee!" said Murgatroyd cordially. "Chee-chee!"
The stark incredulity of the bearded face changed to shock. That expression became purest desperation. One of Doctor Kelo's beautifully manicured hands disappeared. It appeared again. There was a tiny snapping sound and the grid operator became suddenly boneless. He seemed to bend limply in all his joints and almost to pour downward to the floor.
Doctor Kelo turned swiftly to the dials of the landing-grid control-board. He surveyed them, panting suddenly. Of course, a landing grid can do its work in many different fashions. It can use the processes of normal space commerce to make space war impossible. Because it can be deadly.
Doctor Kelo reached out. Calhoun could not see exactly what he did, but he could guess its purpose. Immediately he felt a surging of the Med Ship which told him exactly what had been done. It was an increased downward velocity of the ship, which had to be brought down rapidly for most of its descent, or otherwise the grid would swing around to the night side of this world where, with a planet's bulk between, it could not do anything with the Med Ship at all. However, high acceleration toward the ground could be used to a certain point only. Below a critical distance the ship couldn't be stopped. It would be bound to crash to flaming destruction against the world it had meant to land on.
The ship surged again. It plunged planetward with doubled acceleration. In the grip of the landing grid's force fields, it built up to a velocity far beyond any at which it could be slowed for a safe landing. It was building up toward the speed of shooting stars, which consume themselves when they touch atmosphere. It was still thousands of miles out in emptiness, still speeding crazily to inevitable destruction.
V
Calhoun said coldly, "I've got to learn how a murderer thinks, Murgatroyd. While I'm thinking there's a situation they have to meet, these characters work out a way to kill me, as if that was bound to settle everything. I can't anticipate the ideas they get automatically!"
He placed his hands on the control-board where he could act in an infinitesimal fraction of a second. He waited. The Med Ship was in the grip of an immaterial field of force which was capable of handling a merchant ship of space, whereas the Aesclipus Twenty was as small as a ship could be and still perform a Med Ship's functions.
The fact that a field of force is not a solid object has its consequences. A solid object can exert a thrust in three dimensions. If it is rigid, it can resist or impose thrusts in any direction, up or down, right or left, and away from or toward itself. However, a field of force can only act in one: toward or away from, or up or down, or left or right. It cannot push in one direction while resisting a thrust from another. So a grid field could pull a ship downward with terrific force, but it could not pull the ship sidewise at the same moment, and that happened to be what was necessary.