There were small scout-ships which came on ahead of the main fleet. They'd originally been guard-boats, intended for solar-system duty only and quite incapable of overdrive. They'd come from Weald in the cargo-holds of the liners now transformed into fighting ships. The scouts swept low, transmitting fine-screen images back to the fleet, of all that they might see before they were shot down. They found the landing-grid. It contained nothing larger than Calhoun's Med Ship, Aesclipus Twenty.

They searched here and there. They flitted to and fro, scanning wide bands of the surface of Dara. The planet's cities and highways and industrial centers were wholly open to inspection from the sky. It looked as if the scouts hunted most busily for the fleet of former grain-ships which Calhoun had said blueskins had seized and rushed away. If the scouts looked for them, they did not find them.

Dara offered no opposition to the scout-ships. Nothing rose to space to oppose or to resist their search. They went darting over every portion of the hungry planet, land and seas alike, and there was no sign of military preparedness against their coming. The huge ships of the main fleet waited while they reported monotonously that they saw no sign of the stolen fleet. But the stolen fleet was the only means by which the planet could be defended. There could be no point in a pitched battle in emptiness. But a fleet with a planet to back it might be dangerous.

Hours passed. The Wealdian main fleet waited. There was no offensive movement by the fleet. There was no defensive action from the ground, With fusion-bombs certain to be involved in any actual conflict, there was something like an embarrassed pause. The Wealdian ships were ready to bomb. They were less anxious to be vaporized by possible suicide-dashes of defending ships who might blow themselves up near contact with their enemies.

But a fleet cannot travel some light-years through space to make a mere threat. And the Wealdian fleet was furnished with the material for total devastation. It could drop bombs from hundreds, or thousands, or even tens of thousands of miles away. It could cover the world of Dara with mushroom clouds springing up and spreading to make a continuous pall of atomic-fusion products. And they could settle down and kill every living thing not destroyed by the explosions themselves. Even the creatures of the deepest oceans would die of deadly, purposely-contrived fallout particles.

The Wealdian fleet contemplated its own destructiveness. It found no capacity for defense on Dara. It moved forward.

But then a message went out from the capital city of Dara. It said that a ship in overdrive had carried word to a Darian fleet in space. The Darian fleet now hurtled toward Weald. It was a fleet of thirty-seven giant ships. They carried such-and-such bombs in such-and-such quantities. Unless its orders were countermanded, it would deliver those bombs on Weald—set to explode. If Weald bombed Dara, the orders could not be withdrawn. So Weald could bomb Dara. It could destroy all life on the pariah planet. But Weald would die with it.

The fleet ceased its advance. The situation was a stalemate with pure desperation on one side and pure frustration on the other. This was no way to end the war. Neither planet could trust the other, even for minutes. If they did not destroy each other simultaneously, as now was possible, each would expect the other to launch an unwarned attack at some other moment. Ultimately one or the other must perish, and the survivor would be the one most skilled in treachery.

But then the pariah planet made a new proposal. It would send a messenger-ship to stop its own fleet's bombardment if Weald would accept payment for the grain-ships and their cargoes. It would pay in ingots of iridium and uranium and tungsten—and gold if Weald wished it—for all damages Weald might claim. It would even pay indemnity for the miners of Orede, who had died by accident but perhaps in some sense through its fault. It would pay.... But if it were bombed, Weald must spout atomic fire and the fleet of Weald would have no home planet to return to.

---

This proposal seemed both craven and foolish. It would allow the fleet of Weald to loot and then betray Dara. But it was Calhoun's idea. It seemed plausible to the admirals of Weald. They felt only contempt for blueskins. Contemptuously, they accepted the semi-surrender.

The broadcast waves of Dara told of agreement, and wild and fierce resentment filled the pariah planet's people. There was almost—almost!—revolution to insist upon resistance, however hopeless and however fatal. But not all of Dara realized that a vital change had come about in the state of things on Dara. The enemy fleet had not a hint of it. And therefore—

In menacing array, the invading fleet spread itself about the skies of Dara, well beyond the atmosphere. Harsh voices talked with increasing arrogance to the landing-grid staff. A monster ship of Weald came heavily down, riding the landing-grid's force-fields. It touched gently. Its occupants were apprehensive, but hungry for the loot they had been assured was theirs. The ship's outer hull would be sterilized before it returned to Weald, of course. And there was adequate protection for the landing-party.

Men came out of the ship's ports. They wore the double, transparent sag-suits Calhoun had suggested, which had been painstakingly tested, and which were perfect protection against contagion. They could loot with impunity, and all contamination would remain outside the suits. What loot they gathered, obviously, could be decontaminated before it was returned to Weald. It was a most satisfactory discovery, to realize that blueskins could be not only scorned but robbed. There was only one bit of relevant information the space-fleet of Weald did not have.

That information was that the people of Dara weren't blueskins any longer. There'd been a trivial epidemic.

The sag-suited men of Weald went zestfully about their business. They took over the landing-grid's operation, driving the Darian operators away. For the first time in history the operators of a landing-grid wore makeup to look like they did have blue pigment in their skins. The Wealdian landing-party tested the grid's operation. They brought down another giant ship. Then another. And another.

Parties in the shiny sag-suits spread through the city. There were the huge stock-piles of precious metals, brought in readiness to be surrendered and carried away. Some men set to work to load these into the holds—to be sterilized later. Some went forthrightly after personal loot.

They came upon very few Darians. Those they saw kept sullenly away from them. They entered shops and took what they fancied. They zestfully removed the treasure of banks.

Triumphal and scornful reports went up to the hovering great ships. The blueskins, said the reports were spiritless and cowardly. They permitted themselves to be robbed. They kept out of the way. It had been observed that the population was streaming out of the city, fleeing because they feared the ships' landing-parties. The blueskins had abjectly produced all they'd promised of precious metals, but there was more to be taken.

More ships came down, and more. Some of the first, heavily loaded, were lifted to emptiness again and the process of decontamination of their hulls began. There was jealousy among the ships in space for those upon the ground. The first-landed ships had had their choice of loot. There were squabblings about priorities, now that the navy of Weald plainly had a license to steal. There was confusion among the members of the landing-parties. Discipline disappeared. Men in plastic sag-suits roved about as individuals, seeking what they might loot.

---

There were armed and alerted landing-parties around the grid itself, of course, but the capital city of Dara lay open. Men coming back with loot found their ships already lifted off to make room for others. They were pushed into reËmbarking-parties of other ships. There were more and more men to be found on ships where they did not belong, and more and more not to be found where they did. By the time half the fleet had been aground, there was no longer any pretense of holding a ship down until all its crew returned. There were too many other ships' companies clamoring for their turn to loot. The rosters of many ships, indeed, bore no particular relationship to the men actually on board.

There were less than fifteen ships whose to-be-fumigated holds were still empty, when the watchful government of Dara broadcast a new message to the invaders. It requested that the looting stop. No matter what payment Weald claimed, it had taken payment five times over. Now was time to stop.

It was amusing. The space-admiral of Weald ordered his ships alerted for action. The message-ship, ordering the Darian fleet away from Weald, had been sent off long since. No other ship could get away now! The Darians could take their choice; accept the consequences of surrender, or the fleet would rise to throw down bombs.

Calhoun was asking politely to be taken to the Wealdian admiral when the trouble began. It wasn't on the ground, at all. Everything was under splendid control where a landing-force occupied the grid and all the ground immediately about it. The space admiral had headquarters in the landing-grid office. Reports came in, orders were issued, admirably crisp salutes were exchanged among sag-suited men.... Everything was in perfect shape there.

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 space-port 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 means 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, that has been aground today, that 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. "When you ordered all ships alerted for action, the Darians on each ship released panic-gas. They only needed tiny, pocket-sized containers of the gas for the job. They had them. They only needed to use air-tanks from their sag-suits to protect themselves against the gas. They kept them handy. On nearly all your ships aloft your crews are crazy from panic-gas. They'll stay that way until the air is changed. Darians have barricaded themselves in the control-rooms of most if not all your ships. You haven't got a fleet. If the few ships that will obey your orders, drop one bomb, our fleet off Weald will drop fifty. I don't think you'd better order offensive action. Instead, I think you'd better have your fleet medical officers come and learn some of the facts of life. There's no need for war between Dara and Weald, but if you insist...."

The Admiral made a choking noise. He could have ordered Calhoun killed, but there was a certain appalling fact. The men aground from the fleet were breathing Wealdian air from tanks. It would last so long only. If they were taken on board the still obedient ships overhead, Darians would unquestionably be mixed with them. There was no way to take off the parties now aground without exposing them to contact with Darians, on the ground or in the ships. There was no way to sort out the Darians.

"I—I will give the orders," said the admiral thickly. "I—do not know what you devils plan, but—I don't know how to stop you."

"All that's necessary," said Calhoun warmly, "is an open mind. There's a misunderstanding to be cleared up, and some principles of planetary health practises to be explained, and a certain amount of prejudice that has to be thrown away. But nobody need die of changing their minds. The Interstellar Medical service has proved that over and over!"

Murgatroyd, perched on his shoulder, felt that it was time to take part in the conversation. He said;

"Chee-chee!"

"Yes," agreed Calhoun. "We do want to get the job done. We're behind schedule now."

---

It was not, of course, possible for Calhoun to leave immediately. He had to preside at various meetings of the medical officers of the fleet with the health officials of Dara. He had to make explanations, and correct misapprehensions, and delicately suggest such biological experiments as would prove to the doctors of Weald that there was no longer a plague on Dara, whatever had been the case three generations before. He had to sit by while an extremely self-confident young Darian doctor named Korvan rather condescendingly demonstrated that the former blue pigmentation was a viral product quite unconnected with the plague, and that it had been wiped out by a very trivial epidemic of—such and such. Calhoun regarded that young man with a detached interest. Maril thought him wonderful, even if she had to give him the material for his work. Calhoun shrugged and went on with his work:

The return of loot. Mutual, full, and complete agreement that Darians were no longer carriers of plague, if they had ever been. Unless Weald convinced other worlds of this, Weald itself would join Dara in isolation from neighboring worlds. A messenger ship to recall the twenty-seven ships once floating in orbit about Weald. Most of them would be used for some time, now, to bring beef from Orede. Some would haul more grain from Weald. It would be paid for. There would be a need for commercial missions to be exchanged between Weald and Dara.

It was a full week before he could go to the little Med Ship and prepare for departure. Even then there were matters to be attended to. All the food-supplies that had been removed could not be replaced. There were biological samples to be replaced and some to be destroyed.... The air-tanks....

Maril came to the Med Ship again when he was almost ready to leave. She did not seem comfortable.

"I wish you could like Korvan," she said regretfully.

"I don't dislike him," said Calhoun. "I think he will be a most prominent citizen, in time. He has all the talents for it."

Maril smiled very faintly.

"But you don't admire him."

"I wouldn't say that," protested Calhoun. "After all, he is attractive to you, which is something I couldn't manage."

"You didn't try," said Maril. "Just as I didn't try to be fascinating to you. Why?"

Calhoun spread out his hands. But he looked at Maril with respect. Not every woman could have faced the fact that a man did not feel impelled to make passes at her. It is simply a fact that has nothing to do with desirability or charm or anything else.

"You're going to marry him," he said. "I hope you'll be very happy."

"He's the man I want," said Maril frankly. "He looks forward to splendid discoveries. I'm sorry it's so important to him."

Calhoun did not ask the obvious question. Instead, he said thoughtfully;

"There's something you could do.... It needs to be done. The Med Service in this sector has been badly handled. There are a number of—discoveries that need to be made. I don't think your Korvan would relish having things handed to him on a visible silver platter. But they should be known...."

Maril said wrily;

"I can guess what you mean. I never went into detail about how the blueskin markings disappeared, but a few hints—You've got books for me?"

Calhoun nodded. He brought them to her.

"If we only fell in love with each other, Maril, we'd be a team! Too bad! These are a wedding present you'll do well to hide."

She put her hands in his.

"I like you—almost as much as I like Murgatroyd! Yes! Korvan will never know, and he'll be a great man." Then she added defensively, "And not just from these books! He'll make his own wonderful discoveries."

"Of which," said Calhoun, "the most remarkable is you. Good luck Maril!"

---

Presently the Med Ship lifted. Calhoun aimed it for the next planet on the list of those he was to visit. After this one more he'd return to sector headquarters with a biting report to make on the way things had been handled before him. He said;

"Overdrive coming, Murgatroyd!"

Then the stars went out and there was silence, and privacy, and a faint, faint, almost unhearable series of background sounds which kept the Med Ship from being totally unendurable.

Long, long days later the ship broke out of overdrive and Calhoun guided it to a round and sunlit world. In due time he thumped the communicator-button.

"Calling ground," he said crisply. "Calling ground! Med Ship Aesclipus Twenty reporting arrival and asking coÖrdinates for landing. Purpose of landing, planetary health inspection. Our mass is fifty standard tons."

There was a pause while the beamed message went many, many thousands of miles. Then the speaker said;

"Aesclipus Twenty, repeat your identification!"

Murgatroyd said;

"Chee-chee? Chee?"

Calhoun sighed.

"That's right, Murgatroyd! Here we go again!"

THE END