Calhoun said curtly:
"Med Ship to Control. I've something to tell you. Suppose you listen. But not on spacephone. Have your best grid technician come outside and then I shall tell him by speaker."
He snapped off the spacephone and watched. The control building fairly erupted indignant youths. After a moment he saw the gangling one who'd grinned so proudly when the Med Ship was landed with absolute perfection. The others shouted and scowled at the ship.
Calhoun threw on the outside speaker—normally used for communication with a ground crew before lifting.
"I'm set," said Calhoun coldly, "for overdrive travel. My Duhanne cells are charged to the limit. If you try to form a force-field around this ship, I'll dump half a dozen overdrive charges into it in one jolt that will blow every coil you've got! And then how'll you fight the ships from Phaedra? I'm going to talk to them on spacephone. Listen in if you like. Monitor it. But don't try to bother me!"
He threw on the spacephone again and patiently resumed his calling:
"Med Ship Aesclipus Twenty calling fleet from Phaedra! Med Ship calling fleet from Phaedra—"
He saw violent argument outside the grid's control building. Some of the young figures raged. But the youth who'd handled the grid so professionally raged at them. Calhoun hadn't made an idle threat. A grid-field could be blown out. A grid could be made useless by one of the ships it handled. When a ship like Calhoun's went into overdrive, it put out something like four ounces of pure energy to form a field in which it could travel past the speed of light. In terms of horsepower or kilowatt hours, so much force would be meaningless. It was too big. It was a quantity of energy whose mass was close to four ounces. When the ship broke out of overdrive, that power was largely returned to storage. The loss was negligible, compared to the total. But, turned loose into a grid's force-field, even three or four such charges would work havoc with the grid's equipment.
Calhoun got an answer from emptiness just as the members of the group by the control building shouted each other down and went inside to listen with bitter unease and suspicion to his talk with the enemy.
"Phaedra fleet calling," said a growling voice in the spacephone speaker. "What do you want?"
"To exercise my authority as a Med Service officer," said Calhoun heavily. "I warn you that I now declare this planet under quarantine. All contact with it from space is forbidden until health hazards here are under control. You will inform all other spacecraft and any other spaceport you may contact of this quarantine. Message ends."
Silence. A long silence. The growling voice rasped:
"What's that? Repeat it!"
Calhoun repeated it. He switched off the phone and unpacked the throat-swabbings he'd made at the four children's shelters in turn. He opened up his laboratory equipment. He put a dilution of one throat-swabbing into a culture slide that allowed living organisms to be examined as they multiplied. He began to check his highly specific suspicions. Presently he was testing them with minute traces of various antibodies. He made rough but reasonably certain identifications. His expression grew very, very sober. He took another swab sample and put it through the same process. A third, and fourth, and fifth, and tenth. He looked very grim.
It was sunset outside when there was a hammering on the ship's hull. He switched on a microphone and speaker.
"What do you want?" he asked flatly.
The angry voice of young Walker came from the gathering darkness. The screens showed a dozen or more inhabitants of Canis III milling angrily about him. Some were of the young-warrior age. They engaged in bitter argument. But the younger Walker, and four or five with him, faced the ship with ominous quietness.
"What's this nonsense about quarantine?" demanded Walker harshly, from outside. "Not that we've space-commerce to lose, but what does it mean?"
"It means," Calhoun told him, "that your brave new world rates as a slum. You've kept kids quiet with psych circuits, and they haven't eaten properly and haven't exercised at all. They're weak from malnutrition and feeble from not doing their own playing. They're like slum children used to be in past ages. Here on Canis you're about ready to wipe yourselves out. You may have done it."
"You're crazy!" snapped Walker. But he was upset.
"In the four shelters I visited," Calhoun said drearily, "I spotted four cases of early diphtheria, two of typhoid, three of scarlet fever and measles, and samples of nearly any other disease you care to name. The kids have been developing those diseases out of weakness and from the reservoir of infections we humans always carry with us. They'd reached the contagious stage before I saw them—but all the kids are kept so quiet that nobody noticed that they were sick. They've certainly spread to each other and their nurses, and therefore out into your general population, all the infections needed for a first-rate multiple epidemic. And you've no doctors, no antibiotics—not even injectors to administer shots if you had them."
"You're crazy!" cried the young Walker. "Crazy! Isn't this a Phaedra trick to make us give in?"
"Phaedra's trick," said Calhoun more drearily than before, "is an atom bomb they're going to drop into this landing grid—I suspect quarantine or no quarantine—in just two days more. Considering the total situation, I don't think that matters."
VI
" . . . The most difficult of enterprises is to secure the co-operation of others in enterprises those others did not think of first . . ."
Manual, Interstellar Medical Service. P. 189.
Calhoun worked all night, tending and inspecting the culture incubators which were part of the Med Ship's technical equipment. In the children's shelters, he'd swabbed throats. In the ship, he'd diluted the swabbings and examined them microscopically. He'd been depressingly assured of his very worst fears as a medical man—all of which could have been worked out in detail from the psych circuit system of child care boastfully described by Fredericks. He could have written out his present results in advance from a glance at the child Jak shown him by the younger Walker's wife. But he hated to find that objective information agreed with what he would have predicted by theory.
In every human body there are always germs. The process of good health is in part a continual combat with slight and unnoticed infections. Because of victories over small invasions, a human body acquires defenses against larger invasions of contagion. Without such constant small victories, a body ceases to keep its defenses strong against beachheads of infection. Yet malnutrition or even exhaustion can weaken a body once admirably equipped for this sort of guerilla warfare.
If an undernourished child fails to win one skirmish, he can become overwhelmed by a contagion the same child would never have known about had he only been a little stronger. But, overwhelmed, he is a sporadic case of disease—a case not traceable to another clinical case. And then he is the origin of an epidemic. In slum conditions a disease not known in years can arise and spread like wildfire. With the best of intentions and great technical ingenuity, the younger-generation colonists of Canis III had made that process inevitable among the younger children who were their last-imposed burden. The children were under-exercised, under-stimulated, and hence under par in appetite and nutrition. And it is an axiom of the Med Service that a single underfed child can endanger an entire planet.
Calhoun proved the fact with appalling certainty. His cultures astounded even him. But by dawn he had applied Murgatroyd's special genetic abilities to them. Murgatroyd said "Chee!" in a protesting tone when Calhoun did what was necessary at that small patch on his flank which was quite insensitive. But then Murgatroyd shook himself and admiringly scowled back at Calhoun, imitating the intent and worried air that Calhoun wore. Then he followed Calhoun about in high good spirits, strutting on his hind legs, man-fashion, and pretending to set out imaginary apparatus as Calhoun did, long ahead of time for what he hoped would occur.