o
bombs--a concession by Calhoun--and plastic factories make an
astonishing number of plastic sag-suits. And large shipments of heavy
metals in ingots would be made to the planet's capital city and there
would be some guns and minor items....

Perhaps somebody could have found out any of these items in advance, but
it was unlikely that anybody did. Nobody but Calhoun, however, would
ever have put them together and hoped very urgently that that was the
way things would work out. He could see a promising total result. In
fact, in the Med ship hurtling through space, on the fourth day of his
journey he thought of an improvement that could be made in the sum of
all those happenings when they were put together.

* * * * *

He landed on Dara. Maril came to the Med Ship. Murgatroyd greeted her
with enthusiasm.

"Something unusual has happened," said Maril, very much subdued. "I told
you that--sometimes blueskin markings fade out on children, and then
neither they nor their children ever have blueskin markings again."

"Yes," said Calhoun. "I remember."

"And you were reminded of a group of viruses on Tralee. You said they
only took hold of people in terribly bad physical condition, but then
they could be passed on from mother to child. Until--sometimes--they
died out."

Calhoun blinked.

"Yes...."

"Korvan," said Maril very carefully, "Has worked out an idea that that's
what happens to the blueskin markings on--us Darians. He thinks that
people almost dead of the plague could get the--virus, and if they
recovered from the plague pass the virus on and--be blueskins."

"Interesting," said Calhoun, noncommittally.

"And when we went to Weald," said Maril very carefully indeed, "you were
working with some culture-material. You wrote quite a lot about it in
the ship's log. You gave yourself an injection. Remember? And
Murgatroyd? You wrote down your temperature, and Murgatroyd's?" She
moistened her lips. "You said that if infection passed between us,
something would be very infectious indeed?"

"What are you driving at?"

Maril continued slowly. "Th--thousands of people are having their
pigment-spots fade away. Not only children but grownups. And--Korvan has
found out that it always seems to happen after a day when they felt
feverish and very thirsty--and then felt all right again. You tried out
something that made you feverish and thirsty. I had it too, in the ship.
Korvan thinks th