* * *

NAPOLEON SOLO faced the sweating Army man. Caslow looked from Solo to the eager face of Penny Parsons. The Army man looked past them both to the locked door as if hoping for help, for a miracle.

"You might as well tell us," Solo said. "Something happened on that last flight."

"No!" Caslow cried.

The trapped captain still looked toward the door as though he expected someone or something to come through its solid steel. With the help of Penny Parsons, in whom he had confided, Solo had managed to get Caslow alone, away from Wozlak. Now the Army captain sweated.

"You've been making flights to somewhere," Solo insisted. "After your vacation you started staying out too long on your test flights, both you and Wozlak."

"We've had trouble with the ships!"

"No one else has had that trouble. I've checked the flight reports," Solo said.

"So we got two bad ships!"

"Both of you? And then you coincidentally come down with a strange disease?"

Penny Parsons burst out. "Tell him, Mark! I know you're in some trouble. It's that Wozlak, he put you into trouble—I knew he would."

"Shut up, Penny!"

The Army man was deadly pale. "You've got to tell Mr. Solo. He can—" the girl began.

Caslow turned even whiter. "Mr.—who?"

"Solo," the agent said. "My real name is Napoleon Solo, and I work for the same people Diaz did."

"Diaz?" Caslow almost whispered. "No."

"You know what happened to him, don't you, Caslow?"

But Caslow did not seem to hear. He was staring into space.

"U.N.C.L.E.! You're with U.N.C.L.E.," Caslow whispered.

"Tell me what happened to Diaz, and what you're mixed up in! We know, Caslow. We'll find out what it is," Solo said.

"No more," Caslow whispered. "Don't ask any more!"

Penny Parsons insisted. "Please, Mark, tell Mr. Solo!"

"No more! You don't understand! No more!"

Solo leaned close to the sweating officer. His handsome face was grim as he stared into Caslow's eyes. His voice was low and insistent.

"We'll have to turn you over to the CIA. You realize that? You might as well tell us. If you don't I'll have to take you back to New York. We'll use pentathol, and—"

Complete terror filled the eyes of the Army man. He seemed to be in the grip of a titanic struggle. Then he went limp.

"All right," Caslow said. "I'll tell you what you want to know."

There was a small, sharp explosion. A tiny puff of smoke appeared over Caslow's heart. The army man screamed once and fell off his chair to the floor. There was blood. Penny Parsons stared in horror and then uttered a small cry.

Solo bent over the man. Caslow was dead. Solo opened the uniform coat, looked.

"Thrush. It's their trick," Solo said. "A lethal charge inserted under the skin over the heart. It must have been programmed into his blood pressure."

Penny Parsons stammered. "Blood pressure? Programmed?"

Solo nodded. "Probably works like a lie-detector. Set to explode when a change in blood pressure indicates a man under interrogation cracks, decides to talk. The blood pressure would show that. Typical Thrush tactics. I should have guessed."

"Who is Thrush?" Penny asked.

"It's better that you don't know, Penny," Solo said. He looked down at the dead Caslow. He felt sorry for the man, it was a hard way to go. Still, there was no doubt that Caslow and Wozlak were somehow involved with Thrush. "What you don't know can't get you to end up like this."

"But I do know," Penny said, "Don't I? I mean, I know about Mark and that awful Wozlak, and I know about you, and—"

"I get the point," Solo said. "All right. It's possible we could use you anyway. Let's go, before Major Smart gets smart and starts looking for Caslow. I don't think the major would care for our explanation of how Caslow died."

"Go? Go where?" the lab girl said.

"Why, New Mexico, of course. I imagine we'll find our friend Wozlak there somewhere," Solo said.

"But I can't get time off to—"

"That will be arranged, Penny," Solo said. "New Mexico is the next piece of the puzzle. I think we will find more than our friend Wozlak —a lot more."

THREE

THE LINE of low brown hills was farther away than Illya Kuryakin had imagined. All afternoon, through the blazing sun and heat of the barren New Mexico land, he had walked toward them. Land fit only to be given to the sad remnants of a proud people.

As he walked in the heat Illya wondered again at the hypocrisy of those who were shocked by Siberia but blind to the equal horror visited upon the Indians. At least, in Siberia, the condemned sometimes got their release.

It was night when Illya at last reached the line of low hills. Moving carefully, he made his way up in the dark of the desert night. He reached the crest without seeing or hearing anything. He crawled the last few feet and looked over and out.

He saw a long, narrow valley, dark and indistinct in the night. Apparently, it was barren and empty. And yet there was something odd. Nothing moved; there was no ray of light. Yet Illya had the feeling that something, someone, was down there. He opened his small suitcase and took out a pair of infra-red binoculars.

Through the glasses the details were clearer in the night. There was nothing he could put his finger on, but he still sensed that something was odd down there. He watched for some hours, but there was neither light nor movement anywhere in the long, narrow valley below. There seemed to be no defenses of any kind.

Could he be wrong? He remembered the nail-studded two-by-four on the highway. Had they set a trap to divert him, send him on a wild goose chase? It was possible, yet he did not think so. Somewhere down there was the strange black craft that flew so fast it glowed red.

At midnight, Illya Kuryakin decided there was nothing more he could do until dawn. He needed sleep. He found a small, but deep culvert on the other side of the hills, and crawled in. He checked all approaches, set out four tiny alarm cells so that no one could approach without warning, and then lay down to sleep because it would be a long day tomorrow and he needed all his strength.

* * *

IN THE telephone booth at the Elk River airport, Maxine Trent looked out through the glass sides at a twin-engine plane taxiing down the runway. The deep voice at the other end of the telephone line was concerned.

"Solo is leaving Elk River? Why? He could not have found anything, at least not so quickly. The computer said U.N.C.L.E. could learn nothing at all from Wozlak or Caslow."

"Did the computer know about the girl?" Maxine said into the black instrument, her eyes still following the small plane on the runway.

"Girl? What girl?"

"Caslow's girl friend, a Penny Parsons," Maxine said. "Now Caslow's dead, and Solo and the girl are flying out to New Mexico."

The deep voice swore. "Caslow's dead?"

"The programmed destruct device worked. He was about to talk," Maxine reported. "It seems he neglected to tell us that he had a girlfriend, and our agents failed to detect her."

"Someone will pay!" the deep voice snarled. "And Wozlak? What about him?"

"Escaped to New Mexico. With Solo on to Caslow, Wozlak was no more use here," Maxine said.

The voice cursed again. "Follow Napoleon Solo, alert our people at Noche Triste. The computer did not know about the girl."