with Murgatroyd riding on his
shoulder. A bewildered officer in a sag-suit halted him.

"I've come," said Calhoun, "to speak to the admiral. My name is
Calhoun and I'm Med Service, and I think I met the admiral at a
banquet a few weeks ago. He'll remember me."

"You'll have to wait," protested the officer. "There's some trouble--"

"Yes," said Calhoun. "I know about it. I helped design it. I want to
explain it to the admiral. He needs to know what's happened, if he's
to take appropriate measures."

There were jitterings. Many men in sag-suits had still no idea that
anything had gone wrong. Some appeared, brightly carrying loot. Some
hung eagerly around the airlocks of ships on the grid tarmac, waiting
their turns to stand in corrosive gases for the decontamination of
their suits, when they would burn the outer layers and step, aseptic
and happy, into a Wealdian ship again. There they could think how rich
they were going to be back on Weald.

But the situation aloft was bewildering and very, very ominous. There
was strident argument. Presently Calhoun stood before the Wealdian
admiral.

"I came to explain something," said Calhoun pleasantly. "The situation
has changed. You've noticed it, I'm sure."

The admiral glared at him through two layers of plastic, which covered
him almost like a gift-wrapped parcel.

"Be quick!" he rasped.

"First," said Calhoun, "there are no more blueskins. An epidemic of
something or other has made the blue patches on the skins of Darians
fade out. There have always been some who didn't have blue patches.
Now nobody has them."

"Nonsense!" rasped the admiral. "And what has that got to do with this
situation?"

"Why, everything," said Calhoun mildly. "It seems that Darians can
pass for Wealdians whenever they please. That they _are_ passing for
Wealdians. That they've been mixing with your men, wearing sag-suits
exactly like the one you're wearing now. They've been going aboard
your ships in the confusion of returning looters. There's not a ship
now aloft, which has been aground today, which hasn't from one to
fifteen Darians--no longer blueskins--on board."

The admiral roared. Then his face turned gray.

"You can't take your fleet back to Weald," said Calhoun gently, "if
you believe its crews have been exposed to carriers of the Dara
plague. You wouldn't be allowed to land, anyhow."

The admiral said through stiff lips, "I'll blast--"

"No," said Calhoun, again gently. "W