deceptive. But you can tell."

"That goes to Headquarters at once!" snapped the colonel.

He went out briskly. Coburn followed him out of the room to look for Janice. And Janice happened to be looking for him at exactly the same moment. He was genuinely astonished to realize how relieved he was that she was all right.

He said apologetically: "I was worried! When I felt myself passing out I felt pretty rotten at having failed to protect you."

She looked at him with nearly the same sort of surprised satisfaction. "I'm all right," she said breathlessly. "I was worried about you."

The roaring of motors outside the hospital interrupted them. More and more vehicles arrived, until a deep purring filled the air. A Greek doctor with a worried expression hurried somewhere. Soldiers appeared, hard-bitten, tough, professional Greek soldiers. Hallen came out of a hospital room. The Greek general appeared with one of the two colonels who'd been at the airport. The general nodded, and his eyes seemed cordial. He waved them ahead of him into a waiting elevator. The elevator descended. They went out of the hospital and there was an armored car waiting. An impressive escort of motorcycle troops waited with it.

The Greek general saw Coburn's cynical expression at sight of the guards. He explained blandly that since oxygen brought sleeping Bulgarians out of their slumber—and had been used on them—oxygen was handy for use by anybody who experienced a bright flash of light in his mind. The Bulgarian soldiers, incidentally, said that outside the village of Ardea they'd felt as if the sunlight had brightened amazingly, but they felt no effects for two hours afterward, when they fell asleep at Náousa. So, said the general almost unintelligibly, if anything untoward happened on the way to the airport, everybody would start breathing oxygen. A sensation of bright light would be untoward.

The armored car started off, with motorcyclists crowded about it with weapons ready. But the ride to the airport was uneventful. To others than Janice and Coburn it may even have been tedious. But when she understood the general's explanation, she shivered a little. She leaned insensibly closer to Coburn. He took her hand protectively in his.

They reached the airport. They roared through the gateway and directly out upon the darkened field. Something bellowed and raced down a runway and took to the air. Other things followed it. They gained altitude and circled back overhead. Tiny bluish flickerings moved across the overcast sky. Exhaust flames.

Coburn realized that it was a fighter plane escort.

The huge transport plane that waited for them was dark. They climbed into it and found their seats. When it roared down the unlighted field and took to the air, everything possible had been done to keep anybody from bringing any weapon to bear upon it.

"All safe now!" said the voice of the American colonel in the darkness of the unlit plane, as the plane gained height. "Incidentally, Coburn, why did you want to look at Pangalos' palm? What did you expect to find there?"

"When I started for the airport," Coburn explained, "I bent a pin around the band of a ring I wear. I could let it lie flat when I shook hands. Or I could make it stand out like a spur. I set it with my thumb. I saw Pangalos' eyes, so I had it stand out, and I made a tear in his plastic skin when I shook hands with him. He didn't feel it, of course." He paused. "Did anybody go to the address I gave Hallen?"

Hallen said, in the darkness: "Major Pangalos got there first."

The blackness outside the plane seemed to grow deeper. There was literally nothing to be seen but the instrument dials up at the pilots' end of the ship.

The Greek general asked a question in his difficult English.

"Where'd they come from?" repeated Coburn. "I've no idea. Off Earth, yes. A heavy planet, yes. I doubt they come from our solar system, though. Somewhere among the stars."

The Greek general said something with a sly up-twist of his voice. Whatever and whoever the Invaders were, he said, they did not like Bulgarians. If they'd knocked out the raiding party simply to test their weapons against human subjects, at least they had chosen suitable and pleasing subjects for the test.

There was light. For an instant Coburn tensed. But the plane climbed and the brightness steadied. It was the top of a cloud bank, brilliantly white in the moonlight. They had flown up through it, and it reached as far ahead as they could see. A stubby fighter plane swam up out of the mist and fell into position alongside. Others appeared. They took formation about the transport and all flew steadily through the moonlight.

"I wish I knew," said the American colonel vexedly, "if those creatures were only testing weapons, or if they were getting set to start bargaining with us!"

"Meaning?" asked Coburn.

"If they're here," said the colonel angrily, "and if they do mean to meddle in our business, they may set up a sort of auction with us bidding against the Iron Curtain gang for their friendship. And they'd make any deal!"

The Greek general agreed drily. He said that free people were not practical people. They were always ready to die rather than cease to be free. Surely the Greeks had proved themselves ready to die. But people like the Bulgarians thought that to continue to live was the most important thing in the world. It was, of course, the practical view-point....

"They can have it!" growled Coburn.

Janice said hesitantly: "But the Invaders haven't killed anybody we know of. They could have killed the Bulgarians. They didn't. The one who called himself Dillon stopped one man from killing them. And they could have killed us, earlier today at the airport. Could they want to be friends?"

"They're starting the wrong way," said Coburn.

The Greek general stirred in his seat, but he was pointedly silent.

The pilot snapped abruptly from up at the bow of the plane: "Colonel! sir! Two of the fighters are climbing as if they've spotted something. There go the rest."

Coburn leaned across Janice to stare out the window. When the fighters were below the transport, they could be seen in silhouette against the clouds. Above, their exhaust flames pin-pointed them. Small blue flames climbed steeply.

The big ship went on. The roar of its motors was steady and unvarying. From a passenger seat it was not possible to look overhead. But suddenly there were streaking sparks against the stars. Tracer bullets. Fighters swerved and plunged to intercept something....

And a Thing came down out of the sky with a terrific velocity. Tracer bullets sprayed all around it. Some could be seen to ricochet off its sides. Flashings came from the alien craft. They were not explosions from guns. They were lurid, actinic, smokeless blasts of pure light. The Thing seemed to be made of polished metal. It dodged, trying to approach the transport. The fighters lunged to prevent it. The ghastly game of interception seemed to rush here and there all over the sky.

The strange object was not possibly of human design or manufacture. It had no wings. It left no trail of jet fumes or rocket smoke. It was glittering and mirror-like, and it was shaped almost exactly like two turtle-shells base to base. It was flat and oval. It had no visible external features.

It flung itself about with incredible darts and jerkings. It could stop stock still as no plane could possibly stop, and accelerate at a rate no human body could endure. It tried savagely to get through the swarming fighters to the transport. Its light weapon flashed—but the pilots would be wearing oxygen masks and there were no casualties among the human planes. Once a fighter did fall off in a steep dive, and fluttered almost down to the cloud bank before it recovered and came back with its guns spitting.

That one appeared to end the fight. It came straight up, pumping tracers at the steel flier from below. And