There was no habitable world in the Stellar Directory portion of the ship's records. He tried a larger volume of space. Then a still larger one. Nothing.
He tried for less than a habitability-one world. Individual survival might be possible where a colony could not live. He set the search-unit to work again. It found a world which was airless, a gas-giant world with intolerable gravity, another which had an equatorial temperature of minus sixty degrees at noon. Another . . .
Ultimately, one turned up which looked plausible. It was the third-orbit planet of a Type G sun. It was not unduly remote from Lanke. It was listed under the name Delhi. Shallow, marshy seas. A single continent. Temperature, not unbearable. Life-types not unduly dangerous. Atmosphere typical of third-orbit planets but with .04% of a complex methane-derivative gas, apparently harmless. This data had been sent up from an exploring spaceboat, later lost. There were what was believed to be the ruins of a human settlement, photographed from space. Classed as habitability zero because no ship had ever returned to its home spaceport after landing on it. The inimical factor was assumed to exist in the atmosphere, but was not known.
Here was material for guesses, but nothing more. It threw no light on where the dead man with bad teeth had come from. Calhoun went over all the other reports. No other was even as promising as this.
He had been seven hours in overdrive when the projected letters separated into twins. Every letter doubled. The reading-matter became unreadable. With one eye covered, reading was just barely possible, but he could see nothing with real clarity.
He took his temperature. He felt perfectly well, but he had a high fever and his eyes grew progressively worse. He said grimly to Murgatroyd, "I begin to see some excuse for the doctors on Lanke. Whatever they were afraid of getting, I've got. It's highly infectious, all right!"
Ten hours out from Lanke, his vision cleared again. He could fuse the images from both eyes. He continued to feel perfectly well, but his temperature was half a degree higher than three hours earlier.
"This," he told Murgatroyd, "is not according to the rules! I may have to call on you as a member of the medical profession!"
He gave himself as thorough a physical examination as one can give himself. He used the amplifier-microscope on his saliva, his blood, on every body fluid. Each of them showed a minute, perfectly spherical pigmented microorganism in appalling numbers. As he regarded them on the screen of the amplifier-microscope they broke into halves, became small spheres, grew swiftly and prepared to divide again. Meanwhile, they danced and darted and whirled frantically. The reaction to the Daflos reagents indicated the presence of a deadly toxin.
"And I took precautions!" Calhoun said rather dizzily. "I washed and showered. I could almost have operated with no more attempt at a sterile environment!" He shook his head. "I think I can go a little longer. That dead man was farther along than this. I've time enough to call on you, Murgatroyd."
He looked at himself in the mirror. The curious enlargement of the flesh beside his nose had appeared. He began to get out his equipment. Something occurred to him.
"The Health Minister," he said sardonically, "didn't quarantine me. He sent me off. He had no fear of my reporting anything to headquarters! I should be dead before breakout, and you couldn't run the ship to headquarters and it would never be found." Then he said, "Let's prevent such an unpleasant fate, Murgatroyd!"
He drew a small sample of blood from his arm. He injected it into Murgatroyd where a small patch of skin on the tormal's flank had been desensitized almost as soon as he was born. Murgatroyd made no objection.
Now Murgatroyd went back to his cubbyhole, yawning. He crawled in to doze. Calhoun made a mental note to check his pulse and breathing in half an hour. He himself, felt feverish. His head seemed to rock a little. His eyes went bad again. He saw double. Murgatroyd dozed peacefully. Calhoun doggedly waited for him to react to the microscopic spheres. His heartbeat should go up four or five counts a minute. He might run a degree of fever. He would be sleepy for two hours, or three, or even four. Then he'd wake up and his blood would contain antibodies against the material with which he'd been inoculated. He'd be back in robust health, and able to share it with Calhoun.
It didn't work out that way. When Calhoun went to check his pulse-rate in half an hour, Murgatroyd came wide awake. He said, "Chee!" in an inquiring tone. He scrambled out of his nest, filled with vim and zest for whatever the hour might bright forth. His pulse was normal. His temperature was equally correct.
Calhoun stared at him. Murgatroyd couldn't have looked healthier. He showed no sign of having needed to produce antibodies.
He hadn't. There are some diseases, contagious among animals, to which human beings are immune. There are some from which humans suffer, to which animals are not subject. More than once medical research has been halted while a hunt was made for an experimental animal in which a particular strain of microbes or viruses could live.
The plague of which Lanke was terrified and Calhoun a victim happened to be a plague to which Murgatroyd did not need to form antibodies. He was immune to it by the simple normal chemistry of his body, and there was nothing that Calhoun could do about it. He considered that he would unquestionably die within a certain short number of days or hours. The Med Ship would drive on, to breakout somewhere within a light-year more or less of its destination. From there, it should make a shorter overdrive-hop to a matter or no more than a million miles or two, and then it should use Lawlor Drive within the solar system, on whose planet the Interstellar Medical Service had its headquarters.
But if Calhoun was dead nothing of the sort would happen. The Med Ship would breakout. Murgatroyd might still be alive, but he could do nothing. Eventually he would die, bewildered. The Med Ship would never, never be found so long as time ran on, and Lanke . . .
"Murgatroyd," said Calhoun, "this is a bad business! And you're right in it! I know what I'm up against, but what am I going to do for you?"
Murgatroyd said confidently, "Chee-chee-chee!"
"I'm seeing better," said Calhoun suddenly. "It seems to come in waves of better and worse. Intermittent."
He put his hand to his face to feel the now-marked unresilient stiffened flesh beside his nose. Murgatroyd looked hopefully at the coffee pot. He said, "Chee?" There was nothing to indicate the possibility of anything, not anticipated. There was no reason for anything to happen.
Then, abruptly, everything changed. The Aesclipus Twenty was in overdrive and there was only one thing which even in theory could affect her from outside. It was said that if a ship were in overdrive and all the cosmos exploded, and everything in all the galaxies ceased to be, including the galaxies themselves, that people in a ship in overdrive would not know of the disaster and would not hear the last trumpet until breakout-time came.
But now, here at this moment, Calhoun felt a familiar and monstrous dizziness, and an equally familiar and intolerable nausea, and then all the sensations of a whirling, spinning fall toward nothingness. Simultaneously the little ship's vision screens lighted, the Aesclipus Twenty broke out of overdrive and lay floating in space surrounded by a myriad of stars, and a small but bright red light flashed luridly on the control-board.