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?"