So, the scientists ran experiments on the machine, and they made a discovery of a kind they hadn"t been looking for.

Somebody, they discovered, was picking the brains of the scientists there.

Not the brains of the people working with the telepathy machine.

And not the brains of the people working on the several other Earth-limited projects at Yucca Flats.

They"d been reading the minds of some of the scientists working on the new and highly cla.s.sified non-rocket s.p.a.ce drive.

In other words, the Yucca Flats plant was infested with a telepathic spy. And how do you go about finding a telepath? Malone sighed. Spies that got information in any of the usual ways were tough enough to locate. A telepathic spy was a lot tougher proposition.

Well, one thing about Andrew J. Burris--he had an answer for everything.

Malone thought of what his chief had said: "It takes a thief to catch a thief. And if the Westinghouse machine won"t locate a telepathic spy, I know what will."

"What?" Malone had asked.

"It"s simple," Burris had said. "Another telepath. There has to be one around somewhere. Westinghouse _did_ have one, after all, and the Russians _still_ have one. Malone, that"s your job: go out and find me a telepath."

Burris had an answer for everything, all right, Malone thought. But he couldn"t see where the answer did him very much good. After all, if it takes a telepath to catch a telepath, how do you catch the telepath you"re going to use to catch the first telepath?

[Ill.u.s.tration]

Malone ran that through his mind again, and then gave it up. It sounded as if it should have made sense, somehow, but it just didn"t, and that was all there was to that.

He dropped his cigarette to the ground and mashed it out with the toe of his shoe. Then he looked up.

Out there, over the water, was the Jefferson Memorial. It stood, white in the floodlights, beautiful and untouchable in the darkness. Malone stared at it. What would Thomas Jefferson have done in a crisis like this?

Jefferson, he told himself without much conviction, would have been just as confused as he was.

But he"d have had to find a telepath, Malone thought. Malone determined that he would do likewise. If Thomas Jefferson could do it, the least he, Malone, could do was to give it a good try.

There was only one little problem:

_Where_, Malone thought, _do I start looking?_

II

Early the next morning, Malone awoke on a plane, heading across the continent toward Nevada. He had gone home to sleep, and he"d had to wake up to get on the plane, and now here he was, waking up again. It seemed, somehow, like a vicious circle.

The engines hummed gently as they pushed the big ship through the middle stratosphere"s thinly distributed molecules. Malone looked out at the purple-dark sky and set himself to think out his problem again.

He was still mulling things over when the ship lowered its landing gear and rolled to a stop on the big field near Yucca Flats. Malone sighed and climbed slowly out of his seat. There was a car waiting for him at the airfield, though, and that seemed to presage a smooth time; Malone remembered calling Dr. O"Connor the night before, and congratulated himself on his foresight.

Unfortunately, when he reached the main gate of the high double fence that surrounded the more than ninety square miles of United States Laboratories, he found out that entrance into that sanctum sanctorum of Security wasn"t as easy as he"d imagined--not even for an FBI man. His credentials were checked with the kind of minute care Malone had always thought people reserved for disputed art masterpieces, and it was with a great show of reluctance that the Special Security guards pa.s.sed him inside as far as the office of the Chief Security Officer.

There, the Chief Security Officer himself, a man who could have doubled for Torquemada, eyed Malone with ill-concealed suspicion while he called Burris at FBI headquarters back in Washington.

Burris identified Malone on the video screen and the Chief Security Officer, looking faintly disappointed, stamped the agent"s pa.s.s and thanked the FBI chief. Malone had the run of the place.

Then he had to find a courier jeep. The Westinghouse division, it seemed, was a good two miles away.

As Malone knew perfectly well, the main portion of the entire Yucca Flats area was devoted solely to research on the new s.p.a.ce drive which was expected to make the rocket as obsolete as the blunderbuss--at least as far as s.p.a.ce travel was concerned. Not, Malone thought uneasily, that the blunderbuss had ever been used for s.p.a.ce travel, but--

He got off the subject hurriedly. The jeep whizzed by buildings, most of them devoted to aspects of the non-rocket drive. The other projects based at Yucca Flats had to share what s.p.a.ce was left--and that included, of course, the Westinghouse research project.

It turned out to be a single, rather small white building with a fence around it. The fence bothered Malone a little, but there was no need to worry; this time he was introduced at once into Dr. O"Connor"s office.

It was paneled in wallpaper manufactured to look like pine, and the telepathy expert sat behind a large black desk bigger than any Malone had ever seen in the FBI offices. There wasn"t a sc.r.a.p of paper on the desk; its surface was smooth and shiny, and behind it the nearly transparent Dr. Thomas O"Connor was close to invisible.

He looked, in person, just about the same as he"d looked on the FBI tapes. Malone closed the door of the office behind him, looked for a chair and didn"t find one. In Dr. O"Connor"s office, it was perfectly obvious, Dr. O"Connor sat down. You stood, and were uncomfortable.

Malone took off his hat. He reached across the desk to shake hands with the telepathy expert, and Dr. O"Connor gave him a limp and fragile paw.

"Thanks for giving me a little time," Malone said. "I really appreciate it." He smiled across the desk. His feet were already beginning to hurt.

"Not at all," Dr. O"Connor said, returning the smile with one of his own special quick-frozen brand. "I realize how important FBI work is to all of us, Mr. Malone. What can I do to help you?"

Malone shifted his feet. "I"m afraid I wasn"t very specific on the phone last night," he said. "It wasn"t anything I wanted to discuss over a line that might have been tapped. You see, I"m on the telepathy case."

Dr. O"Connor"s eyes widened the merest trifle. "I see," he said. "Well, I"ll certainly do everything I can to help you."

"Fine," Malone said. "Let"s get right down to business, then. The first thing I want to ask you about is this detector of yours. I understand it"s too big to carry around--but how about making a smaller model?"

"Smaller?" Dr. O"Connor permitted himself a ghostly chuckle. "I"m afraid that isn"t possible, Mr. Malone. I would be happy to let you have a small model of the machine if we had one available--more than happy. I would like to see such a machine myself, as a matter of fact.

Unfortunately, Mr. Malone--"

"There just isn"t one, right?" Malone said.

"Correct," Dr. O"Connor said. "And there are a few other factors. In the first place, the person being a.n.a.lyzed has to be in a specially shielded room, such as is used in encephalographic a.n.a.lysis. Otherwise, the mental activity of the other persons around him would interfere with the a.n.a.lysis." He frowned a little. "I wish that we knew a bit more about psionic machines. The trouble with the present device, frankly, is that it is partly psionic and partly electronic, and we can"t be entirely sure where one part leaves off and the other begins. Very trying. Very trying indeed."

"I"ll bet it is," Malone said sympathetically, wishing he understood what Dr. O"Connor was talking about.

The telepathy expert sighed. "However," he said, "we keep working at it." Then he looked at Malone expectantly.

Malone shrugged. "Well, if I can"t carry the thing around, I guess that"s that," he said. "But here"s the next question: Do you happen to know the maximum range of a telepath? I mean: How far away can he get from another person and still read his mind?"

Dr. O"Connor frowned again. "We don"t have definite information on that, I"m afraid," he said. "Poor little Charlie was rather difficult to work with. He was mentally incapable of co-operating in any way, you see."

"Little Charlie?"

"Charles O"Neill was the name of the telepath we worked with," Dr.

O"Connor explained.