He heard a tapping sound on the Med Ship's hull. He looked at a screen. Two youths stood in the doorway of the control building, leisurely shooting at the Med Ship with sporting weapons.
Calhoun set to work. Sporting rifles were not apt to do much damage.
For an hour, while there was the occasional clanking of a missile against the ship's outer planking, he worked at the infinitely delicate job of separating serum from its antibody content. For another hour he tried to separate the antibody into fractions. Incredibly, it would not separate. It was one substance only.
There was a crackling sound and the whole ship shivered. The screen showed a cloud of smoke drifting away. The members of the grid-guard had detonated some explosive—intended for mining, most likely—against one of the landing-fins.
Calhoun swore. His call to the Phaedrian fleet was the cause. The grid-guard meant to allow no landing. He'd threatened to blow out their controls if they tried to use the grid on the Med Ship, but they wanted it ready for use as a weapon against the space fleet. They couldn't use it against him. He couldn't damage it unless they tried. They wanted him away.
He went back to his work. From time to time, annoyedly, he looked up at the outside. Presently a young-warrior group moved toward the ship, carrying something very heavy. A larger charge of explosive, perhaps.
He waited until they were within yards of the ship. He stabbed the emergency-rocket button. A thin, pencil-like rod of flame shot downward between the landing-fins. It was blue-white—the white of a sun's surface. For one instant it splashed out hungrily before it bored and melted a hole into the ground itself into which to flow. But in that instant it had ignited the covering of the burden the youths carried. They dropped it and fled. The pencil flame bored deeper and deeper into the ground. Clouds of smoke and steam arose.
There was a lurid flash. The burden that the young warriors had abandoned vanished in a flare that looked like a lightning bolt. The ship quivered from the detonation. A crater appeared where the explosive had been.
Calhoun cut off the emergency rocket, which had burned for ten seconds at one-quarter thrust.
Sunset came and night fell for the second time. He noticed, abruptly, that some of the ground-cars from about the control building went racing away. But they did not pass close to the Med Ship in their departure. He labored on. He'd spent nearly thirty hours making cultures from the specimens swabbed from children's throats, and injecting Murgatroyd, and waiting for his reaction, and then separating a tiny quantity of antibody—which would not total more than the dust from a butterfly's wing—from the serum he obtained.
Now he worked on, through the night. Far away—some tens or scores of millions of miles—the hospital ships of the Phaedrian fleet took off from the next outward planet. They would be coming at full speed toward Canis III. They would need the results of the work Calhoun was doing, if they were to prevent an appalling multiple plague which could wipe out all the sacrifice the building of the colony had entailed. But his work had to be exact.
It was tedious. It was exacting. It was exhaustingly time-consuming. He did have the help of previous experience, and the knowledge that the most probable molecular design would include this group of radicals and probably that, and side-chains like this might be looked for, and co-polymers might— But he was bleary-eyed and worn out before dawn came again. His eyes felt as if there were grains of sand beneath their lids. His brain felt dry—felt fibrous inside his skull, as if it were excelsior. But when the first red colors showed in the east, with the towers of the city against them, he had the blueprint of what should be the complex molecule formed in Murgatroyd's furry body.
He had just begun to realize, vaguely, that his work was done, when twin glaring lights came bouncing and plunging across the empty center of the grid. They were extraordinarily bright in the ruddy darkness. They stopped. A man jumped from the ground-car and ran toward the ship.
Calhoun wearily threw on the outer microphones and speakers.
"What's the matter now?" The man was the younger Walker.
"You're right!" called Walker's voice, strained to the breaking point. "There is sickness! Everywhere! There's an epidemic! It's just beginning! People felt tired and peevish and shut themselves away. Nobody realized! But they've got fevers! They're showing rashes! There's some delirium! The smallest children are worst—they were always quiet—but it's everywhere! We've never had real sickness before! What can we do?"
Calhoun said tiredly:
"I've got the design for an antibody. Murgatroyd made it. It's what he's for. The hospital ships from Phaedra are on the way now. They'll start turning it out in quantity and their doctors will start giving everybody shots of it."
Young Walker cried out fiercely:
"But that would mean they'd land! They'd take over! I can't let them land! I haven't the power! Nobody has! Too many of us would rather die than let them land! They lied to us. It's bad enough to have them hovering outside. If they land, there'll be fighting everywhere and forever! We can't let them help us! We won't! We'll fight—we'll die first!"
Calhoun blinked, owlishly.
"That," he said exhaustedly, "is something you have to figure out for yourself. If you're determined to die, I can't stop you. Die first or die second—it's your choice. You make it. I'm going to sleep!"
He cut off the mike and speakers. He couldn't keep his eyes open.
VII
" . . . As a strictly practical matter, a man who has to leave a task that he has finished, and wishes it to remain as he leaves it, usually finds it necessary to give the credit for his work to someone who will remain on the spot and will thereby be moved to protect and defend it so long as he lives . . ."
Manual, Interstellar Medical Service. Pp. 167–8
Murgatroyd tugged at Calhoun and shrilled anxiously into his ear.
"Chee-chee!" he cried frantically. "Chee-chee-chee!"
Calhoun blinked open his eyes. There was a crashing sound and the Med Ship swayed upon its landing fins. It almost went over. It teetered horribly, and then slowly swung back past uprightness and tilted nearly as far in the opposite direction. There were crunching sounds as the soil partly gave way beneath one landing fin.
Then Calhoun waked thoroughly. In one movement he was up and launching himself across the cabin to the control-chair. There was another violent impact. He swept his hand across the row of studs which turned on all sources of information and communication. The screens came on, and the spacephone, and the outside mikes and loud-speakers, and even the planetary communication unit which would have reported had there been any use of the electromagnetic spectrum in the atmosphere of this planet.
Bedlam filled the cabin. From the spacephone speaker a stentorian voice shouted:
"This is our last word! Permit our landing or—"
A thunderous detonation was reported by the outside mikes. The Med Ship fairly bounced. There was swirling white smoke outside the ship. It was mid-morning, now, and the giant lacy structure of the landing grid was silhouetted against a deep-blue sky. There were cracklings from some electric storm perhaps a thousand miles away. There were shoutings, also brought in by the outside mikes.
Two groups of figures, fifty or a hundred yards from the Med Ship, labored furiously over some objects on the ground. Smoke billowed out; then a heavy, blastlike "Boom!" Something came spinning through the air, end over end, with sputtering sparks trailing behind it. It fell close by the base of the upright Med Ship.