There was a succession of loud clicks from a speaker unit on the wall. It was an emergency-wave, unlocking the speaker from its Off position. Then a voice:
"All citizens attention! The Planetary President is about to give you good news about the end of the para epidemic!"
A pause. Then a grave and trembling voice came out of the speakers:
"My fellow-citizens, I have the happiness to report that a vaccine completely protecting normals against the para condition, and curing those already paras, has been developed. Dr. Lett, of the planetary health service, has produced the vaccine which is already in small-scale production and will shortly be available in large quantities, enough for everyone! The epidemic which has threatened every person on Tallien Three is about to end! And to hasten the time when every person on the planet will have the vaccine in the required dosage and at the required intervals, Dr. Lett has been given complete emergency authority. He is empowered to call upon every citizen for any labor, any sum, any sacrifice that will restore our afflicted fellow-citizens to normality, and to protect the rest against falling a victim to this intolerable disease. I repeat: a vaccine has been found which absolutely prevents anyone from becoming a para, and which cures those who are paras now. And Dr. Lett has absolute authority to issue any orders he feels necessary to hasten the end of the epidemic and to prevent its return. But the end is sure!"
The speaker clicked off. Calhoun said wryly:
"Unfortunately, I know what that means. The President has announced the government's abdication in favor of Dr. Lett, and that the punishment for disobeying Lett is—madness."
He drew a deep breath and shrugged his shoulders.
"Come along! Let's get to work!"
IV
As it happened, the timing was critical, though Calhoun hadn't realized it. There were moving lights on the highway to the city at the moment Calhoun and the grid operator went into the Med Ship and closed the air-lock door behind them. The lights drew nearer. They raced. Then ground cars came rushing through the gate of the spaceport and flung themselves toward the wholly peaceful little Med Ship where it stood seeming to yearn toward the sky. In seconds they had it ringed about, and armed men were trying to get inside. But Med Ships land on very many planets, with very many degrees of respect for the Interstellar Medical Service. On some worlds there is great integrity displayed by spaceport personnel and visitors. On others there is pilfering, or worse. So Med Ships are not easily broken into.
They spent long minutes fumbling unskillfully at the outer air-lock door. Then they gave it up. Two car loads of men went over to the control building, which now was dark and silent. Its door was not locked. They went in.
There was consternation. The interior of the control building reeked of antiseptic spray—the spray used when a para was discovered. In some cases, the spray a para used when he discovered himself. But it was not reassuring to the men just arrived from Government Center. Instead of certifying to their safety, it told of horrifying danger. Because despite a broadcast by the planetary president, terror of paras was too well-established to be cured by an official statement.
The men who'd entered the building stumbled out and stammered of what they'd smelled inside the building. Their companions drew back, frightened by even so indirect a contact with supposed contagion. They stayed outside, while a man who hadn't entered used the police-car communicator to report to the headquarters of the planetary police.
The attempt to enter the ship was known inside, of course. But Calhoun paid no attention. He emptied the pockets of the garments he'd worn into the city. There were the usual trivia a man carries with him. But there was also a blaster—set for lower-power bolts—and a small thick-glass phial of a singular grayish fluid, and a plastic container.
He was changing to other clothing when he heard the muttering report, picked up by a ship-receiver tuned to planetary police wave length. It reported affrightedly that the Med Ship could not be entered, and the grid's control building was dark and empty and sprayed as if to destroy contagion. The operator was gone.
Another voice snapped orders in reply. The highest authority had given instructions that the Med Ship man now somewhere in the capital city must be captured, and his escape from the planet must be prevented at all costs. So if the ship itself could not be entered and disabled, get the grid working and throw it away. Throw it out to space! Whether there was contagion in the control building or not, the ship must be made unusable to the Med Ship man!
"They think well of me," said Calhoun. "I hope I'm as dangerous as Dr. Lett now believes." Then he said crisply: "You say you're a para. I want the symptoms: how you feel and where. Then I want to know your last contact with scavengers."
The intentions of the police outside could be ignored. It wouldn't matter if the Med Ship were heaved out to space and abandoned. He was in it. But it couldn't happen. The grid operator had brought away certain essential small parts of the grid control system. Of course the ship could be blown up. But he'd have warning of that. He was safe except for one thing. He'd been exposed to whatever it was that made a man a para. The condition would develop. But he did have a thick-glass container of grayish fluid, and he had a plastic biological-specimen container. One came from Dr. Lett's safest pocket. It would be vaccine. The other came from the culture oven in the doctor's laboratory.
The thick-glass phial was simply that. Calhoun removed the cover from the other. It contained small and horrible squirming organisms, writhing in what was probably a nutrient fluid to which they could reduce human refuse. They swarm jerkily in it so that the liquid seemed to seethe. It smelled. Like skunk.
The grid operator clenched his hands.
"Put it away!" he commanded fiercely. "Out of sight! Away!"
Calhoun nodded. He locked it in a small chest. As he put down the cover he said in an indescribable tone:
"It doesn't smell as bad to me as it did."
But his hands were steady as he drew a sample of a few drops from the vaccine bottle. He lowered a wall panel and behind it there was a minute but astonishingly complete biological laboratory. It was designed for microanalysis—the quantitative and qualitative analysis of tiny quantities of matter. He swung out a miniaturized Challis fractionator. He inserted half a droplet of the supposed vaccine and plugged in the fractionator's power cable. It began to hum.
The grid operator ground his teeth.
"This is a fractionator," said Calhoun. "It spins a biological sample through a chromatograph gele."
The small device hummed more shrilly. The sound rose in pitch until it was a whine, and then a whistle, and then went up above the highest pitch to which human ears are sensitive. Murgatroyd scratched at his ears and complained:
"Chee! Chee! Chee!"
"It won't be long," Calhoun assured him. He looked once at the grid operator and then looked away. There was sweat on the man's forehead. Calhoun said casually: "The substance that makes the vaccine do what it does do is in the vaccine, obviously. So the fractionator is separating the different substances that are mixed together." He added, "It doesn't look much like chromatography, but the principle's the same. It's an old, old trick!"
It was, of course. That different dissolved substances can be separated by their different rates of diffusion through wetted powders and geles had been known since the early twentieth century, but was largely forgotten because not often needed. But the Med Service did not abandon processes solely because they were not new.
Calhoun took another droplet of the vaccine and put it between two plates of glass, to spread out. He separated them and put them in a vacuum drier.