But there was panic among the ships in space. Communicators gave off horrified, panic-stricken yells. There were screamings. Intelligible communications ceased. Ships plunged crazily this way and that. Some vanished in overdrive. At least one plunged at full power into a Darian ocean. The space admiral found himself in command of fifteen ships only out of all his former force. The rest of the fleet went through a period of hysterical madness. In some ships it lasted for minutes only. In others it went on for half an hour or more. Then they hung overhead, but did not reply to calls. Calhoun arrived at the spaceport 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."