Illya grinned faintly from beneath corn-yellow hair.

"Why are you smiling?" This was Solo's voice from the small speaker.

"Because I'm on your candid camera," Illya said.

"Yes. And you will be, " Alexander Waverly told him. "We will attempt to keep this train on camera as long as we can."

"Do you pick up the bleep signal?" Illya asked.

"Loud and clear," Solo answered. It was as if they were not in the command office at U.N.C.L.E. headquarters but were nearer than the train detectives. Still, Illya had a sense of being alone that he could not explain and could not escape.

A slender, Slavic blond man, he was no stranger to peril. Congenitally a loner, he liked solitary assignments.

It seemed to onlookers that he was like a machine. At moments like this nothing existed for him except the assigned task. He'd been born in a country where freedom was taxed and strained and sometimes betrayed; he had learned to despise evil in whatever guise it appeared, to fight it wherever he found it.

Now, Illya felt as if he might be embarking on more than a routine train ride from Pittsburgh to Chicago, his latest assignment from U.N.C.L.E.—the United Network Command for Law and Enforcement.

"You look a little green around the gills," he heard Napoleon Solo saying, knowing that Solo stood beside Waverly in the command room, watching him on closed-circuit television.

"Poor camera work," Illya said casually.

But inwardly, Illya admitted that Solo was perceptive. The unexplained disappearance of a sleek modern streamliner from its tracks belonged to the ghostly unknown, the kind of fantastic stories Illya Kuryakin had heard from superstitious natives in his early childhood.

His mind was coldly analytical, and he had no patience for fantasy. Yet not even the coldest mind could deny that a train, exactly like this one, had vanished, and with it every soul aboard. And without leaving a trace.

It was as if Alexander Waverly read Illya's thought. The receiver crackled as Waverly spoke: "We may not be able to follow the entire run by televised pictures, Illya, but no matter where your train goes, you'll send back a radio bleep. Don't worry—we'll follow you all the way."

The conductor said, "We're ready to roll now, Mr. Kuryakin, if you are."

Illya waved his arm and nodded. He swung aboard the custom-made sleeper that was a precise duplicate of the car in which billionaire philanthropist Harrison Howell had ridden into nothingness.

The sleek streamliner glided along the tracks. Illya prowled the richly appointed car.

"Do you take well to being a rich man, Illya?" Solo inquired via the speaker.

"I was born a billionaire at heart," Illya answered. "I thought you knew."

There was no reply from the command room in New York. Illya turned up the volume on the sender-receiver. "Something gone wrong, Solo?"

Still there was no answer. Illya shook the receiver. The line between him and the command room was open. He was certain of it. There was the urgent crackle, yet neither Solo nor Waverly spoke.

Illya said, "Solo, answer please. Waverly. This is Mayday. Come in, please."

The speaker crackled in his hand. Holding his breath, Illya waited, but no one spoke.

He pressed the sending button. "Come in. Come in. Can you read the bleep-message?"

As if distantly, Illya heard Solo's voice. But Solo was speaking to Waverly, not to Kuryakin: "Can they locate the source of the interference, sir?"

Then Illya heard Waverly, voice sharply impatient: "Negative."

"We better tell Illya the problem," Solo suggested.

"Yes!" Illya spoke loudly into the sender. "Somebody be kind enough to tell me what's going on."

Alexander Waverly's voice came into the private car clearly: "Slight problem here, Illya, but it should not be a major obstacle. Temporarily at least, we've lost the televised picture. When the train got under way, some interference was set.

"We're getting nothing but a jumbled pattern at the moment. We're working on it. Meantime, I assure you the bleep is coming in strong. We're following every mile of your trip. As soon as we get the picture back, we'll let you know. Meantime, I'm sure I don't have to caution you to remain alert."

Illya stood motionless in the private car aisle.

He looked around at the luxurious appointments. Everything was arranged for the animal comfort of men of wealth and power. Men like Harrison Howell.

Howell had been poor in his youth. He'd worked his way through school, majoring in geology. His first job had been with an oil company. Now his holdings in oil ringed the world.

Illya shook his head. When the train bearing Howell had vanished, U.N.C.L.E. had made a routine check into his background, trying to find some hidden evil. The computers found none. Howell had indulged himself, making all the wishful dreams of an under-privileged boy come true, but he had been honest, hard-working, unselfish, patriotic, in no way linked with subversive factions such as THRUSH.

Illya prowled the car. He had searched his own mind for some logical explanation, and had found none.

Assigned to this trip by Alexander Waverly, he had not held much hope for its success.

Now, alone in this car, he could not shake a sense of unexplained, mounting tension.

"Keep busy, Illya," he told himself aloud, for no better reason than that hearing his own voice was reassuring in the eerie silence as the streamliner raced west through the night.

He checked over his own arsenal of latest U.N.C.L.E. designed gimmicks for communication and self-protection. The machine pistol that assembled from light weight parts that served other purposes as well. The small button in his lapel that transmitted its own "bleep" received only in United Command headquarters.

He moved along the aisle, thinking that he was equipped with the latest inventions, and yet he was on a witch-hunting errand. Could fifteen-car trains actually vanish in this modern world?

He could not rid himself of that rising feeling of something wrong.

What could be wrong? He bent over and stared through the thick windows at the night country whipped past on the hundred-mile-an-hour wind drift. Great, rich country, its people sleeping in security in their beds. The wan lights of a midwest village flared by, then the distant glow of a farm house window.

It was all too normal to support the idea of unearthly disappearance; yet, he waited, tense for the unknown into which this train raced.

At the furbished desk, Illya lifted the intra-train phone, pressed the engine button.

After a moment a man's casual voice spoke, "Engineer."

Illya said, "Kuryakin in the special car."

"You living it up, Mr. Kuryakin?" the engineer asked.

"I don't know," Illya said. "That's what I called you to find out."

The engineer laughed. "If it was any smoother, Mr. Kuryakin, we'd be flying."

Illya replaced the phone, aware that he was less than reassured by the engineer's confidence. A train had disappeared a week ago.

Still, hundreds of trains had covered this same tracks, night and day, before and after that strange disappearance.

The railroad people had made every effort to conceal the loss. Failing this, they'd tried to minimize it while they retraced the known run foot by foot. The railings appeared unaltered, there was nothing to suggest any calamity. It was simply as if the fifteen cars, the special sleeper, and all its people had simply ceased to exist.

"We were called in at United Command," Alexander Waverly had told Illya and Solo in the command room three days earlier, "when world-wide panic might ensue if more publicized agencies were at work. We here at the command have determined to make up an exact duplicate of the vanished Chieftain down to the special sleeper in which Harrison Howell rode."