A flat, smooth surface stretched in front of him like a pool of water in the darkness. Then he saw the black object.

"I would suggest speed, Napoleon," Illya said.

Solo smiled. The black object was Illya's head. The sand had just reached the small Russian's chin. As Solo watched, he saw the pale shape that was Illya's right hand.

"Here comes the rope," Solo said.

He tossed the rope. Illya caught it the first time, passed the loop over his hand and into the crook of his elbow. On the boulder Solo began to pull.

Nothing happened.

"The boulder," Illya said.

Solo stepped down carefully, and passed the rope around the boulder. Then he leaned all his weight against the rope end and dug his feet into the hard dirt.

The rope began to give. Solo dug in and struggled ahead, the rope over his shoulder. Suddenly it gave completely and Solo sprawled in the dirt. He jumped up and began pulling more easily.

"All right, enough," Illya called from the other side of the boulder. "I'm out; you'll drag me half over the landscape."

Solo stopped pulling and jumped up to the top of the boulder.

"Ingrate," Solo said, grinning.

Illya, on firm land, stood up and began to pick the thick quicksand from his clothes.

Then the two men moved cautiously back up the arroyo to where Penny Parsons waited. The girl looked nervously around in the dark night.

"Now can we go?" she asked.

"Not until dawn," Illya said. "Much too dangerous to try to go down there again at night."

"You're not going—" Penny began.

Illya shrugged. "Of course. I didn't come here for a swim in quicksand. We still have to find out what there is down there that goes whizz-bang in the night."

Solo handed Illya a spare U.N.C.L.E. special, and the two agents lay down to sleep and wait for the dawn. Penny Parsons sat on the ground and stared at them.

FIVE

MOVING CAUTIOUSLY in the first light of dawn, Illya and Solo reached the yawning black opening beneath the camouflage. They had left Penny securely hidden in a narrow culvert. Now they peered into the maw of the real valley floor beneath the camouflage.

The camouflage reached from one side of the valley to the other, some hundred yards, and rested on supports some fifty feet high. Its length was impossible to estimate—at least two miles along the entire valley floor.

Under the net there were low, flat buildings that almost reached the camouflage above. The buildings told them nothing, and there was no one in sight. Illya pointed to the ground.

"Napoleon, look!"

Solo looked at the ground. He whistled low.

The ground was not ground—it was a smooth cement road. A very wide road, with heavy black marks.

"A runway," Solo said.

"I think we have found where our unidentified flying objects come from," Illya said. He had already described the glowing black craft he had seen fly over him.

"But it's only two miles long, maybe even less."

"Enough with booster rockets," Illya said. "Still, it would take very well trained men to lift off just at the edge there from under the camouflage."

"That's probably why they need expert rocket pilots."

"What I saw flew even faster than a normal rocket," Illya said.

Solo rubbed his chin. "There was radiation around the hole of that explosion. One probably crashed."

"Nuclear propulsion!" Illya said. "And no one has managed to use it for aircraft before."

Solo looked around. "One thing puzzles me. I can see how they manage to take off, but how do they land?"

"Let's find out," Illya said.

The small, blond Russian led the way in a quick dash across the runway to the first low building. The two agents peered in at a window.

Inside the building a horde of black-clad men worked over a long, enormous engine. It was a strange affair, unlike anything Solo or Illya had ever seen.

The agents continued on, running crouched from building to building. Inside another building they saw slabs of black metal-like material glowing in a wind tunnel.

"Heat shield material. That explains the glow on the black plane," Illya said. "At that speed, most materials would melt. They seem to have developed everything."

The third building proved to be a personnel testing installation. Inside it men were seated in big pressure chambers; white-coated men worked over them. There were many glass bottles. As the two agents watched, injections of some pale blue substance were being administered to a group of men.

Then the three armed men came around the corner of the building.

"Quick!" Illya cried.

Solo and Illya ran to a door in the building. It was open. They dashed inside. At the door they listened. The footsteps were approaching the door.

"There," Solo whispered.

A metal door stood open to the left down a dark corridor. Illya and Solo ran for it, entered a large room with benches along the side, and slammed the door shut behind them. Outside in the corridor the footsteps came closer, passed, and faded away.

"Close," Illya said. "Did you see those men being injected, Napoleon?"

Solo nodded. "Yes, I did. I have a hunch that might explain our 'silent malady'. Some effect of a special drug."

"You noticed they were being injected before entering a pressure chamber. I also noticed a jet sled for speed effect testing," Illya said. He nodded soberly. "You know, Napoleon, that black ship I saw moved much faster than anything else I ever heard about. That much speed would have effects on a pilot. I wonder if they have developed a drug of some kind for that purpose, a drug which has side effects?"

"Could be," Solo said. "Let's get out of here and find out."

"An excellent suggestion," Illya said.

The small, blond agent walked in the metal door. He turned the handle, but it would not turn. Illya Kuryakin tried again. Solo watched him. The handle would not turn the fraction of an inch. Solo started toward the door to help.

Solo rose from the floor, floated in the air.

Illya, his hand on the handle of the door, was suddenly above the handle, floating, his body higher than his hand.

Solo floated up and crashed into the metal ceiling. The chief agent tried to force himself down with a lunge. He careened across the room, smashed against a metal wall.

Illya lost his grip on the door handle and tumbled through the air. The small agent cried out.

"Weightless! It's a weightlessness test chamber!"

"You're telling me!" Solo said, floating in the air, smashing against the floor on his back and bounding up.

"We can't handle it!" Illya cried.

"Try!" Solo said.

"It takes training," Illya said, fighting to remain upright in the air, unable to, falling over horizontally.

There was a noise, the sound of metal sliding. The two agents twisted in the air, saw that a metal panel had slid back to show a thick plate glass window. A man's face watched them from the other side of the window.

A fat, round face that smiled benignly at them like a small, pink cherub.

ACT III

ONE EGG IN A CONDOR'S NEST

THE STEEL WALLS of the room were windowless. The door was barred. Penny Parsons sat and was afraid.

"They found me an hour ago. I hoped that you—" she did not finish.

"We'll get you out, Penny," Solo said.