“I don’t quite follow you,” Malone said. Truthfully, he felt about three miles behind. But perhaps everything would clear up soon. He hoped so. On top of everything else, his feet were now hurting a lot more.

“Perhaps if I describe one of the tests we ran,” Dr. O’Connor said, “things will be somewhat clearer.” He leaned back in his chair. Malone shifted his feet again and transferred his hat from his right to his left hand.

“We put one of our test subjects in the insulated room,” Dr. O’Connor said, “and connected him to the detector. He was to read from a book — a book that was not too common. This was, of course, to obviate the chance that some other person nearby might be reading it, or might have read it in the past. We picked The Blood is the Death by Hieronymus Melanchthon, which, as you may know, is a very rare book indeed.”

“Sure,” Malone said. He had never heard of the book, but he was, after all, willing to take Dr. O’Connor’s word for it.

The telepathy expert went on: “Our test subject read it carefully, scanning rather than skimming. Cameras recorded the movements of his eyes in order for us to tell just what he was reading at any given moment, in order to correlate what was going on in his mind with the reactions of the machine’s indicators, if you follow me.”

Malone nodded helplessly.

“At the same time,” Dr. O’Connor continued blithely, “we had Charlie in a nearby room, recording his babblings. Every so often, he would come out with quotations from The Blood is the Death, and these quotations corresponded exactly with what our test subject was reading at the time, and also corresponded with the abnormal fluctuations of the detector.”

Dr. O’Connor paused. Something, Malone realized, was expected of him. He thought of several responses and chose one. “I see,” he said.

“But the important thing here,” Dr. O’Connor said, “is the timing. You see, Charlie was incapable of continued concentration. He could not keep his mind focused on another mind for very long, before he hopped to still another. The actual amount of time concentrated on any given mind at any single given period varied from a minimum of one point three seconds to a maximum of two point six. The timing samples, when plotted graphically over a period of several months, formed a skewed bell curve with a mode at two point oh seconds.”

“Ala,” Malone said, wondering if a skewed ball curve was the same thing as a belled skew curve, and if not, why not?

“It was, in fact,” Dr. O’Connor continued relentlessly, “a sudden variation in those timings which convinced us that there was another telepath somewhere in the vicinity. We were conducting a second set of reading experiments, in precisely the same manner as the first set, and, for the first part of the experiment, our figures were substantially the same. But—” He stopped.

“Yes?” Malone said, shifting his feet and trying to take some weight off his left foot by standing on his right leg. Then he stood on his left leg. It didn’t seem to do any good.

“I should explain,” Dr. O’Connor said, “that we were conducting this series with a new set of test subjects: some of the scientists here at Yucca flats. We wanted to see if the intelligence quotients of the subjects affected the time of contact which Charlie was able to maintain. Naturally, we picked the men here with the highest IQ’s, the two men we have who are in the top echelon of the creative genius class.” He cleared his throat. “I did not include myself, of course, since I wished to remain an impartial observer, as much as possible.”

“Of course,” Malone said without surprise.

“The other two geniuses,” Dr. O’Connor said, “the other two geniuses both happen to be connected with the project known as Project Isle — an operation whose function I neither know, nor care to know, anything at all about.”

Malone nodded. Project Isle was the non-rocket spaceship. Classified. Top Secret. Ultra Secret. And, he thought, just about anything else you could think of.

“At first,” Dr. O’Connor was saying, “our detector recorded the time periods of — ah — mental invasion as being the same as before. Then, one day, anomalies began to appear. The detector showed that the minds of our subjects were being held for as long as two or three minutes. But the phrases repeated by Charlie during these periods showed that his own contact time remained the same; that is, they fell within the same skewed bell curve as before, and the mode remained constant if nothing but the phrase length were recorded.”

“Hmm,” Malone said, feeling that he ought to be saying something.

Dr. O’Connor didn’t notice him. “At first we thought of errors in the detector machine,” he went on. “That worried us not somewhat, since our understanding of the detector is definitely limited at this time. We do feel that it would be possible to replace some of the electronic components with appropriate symbolization like that already used in the purely psionic sections, but we have, as yet, been unable to determine exactly which electronic components must be replaced by what symbolic components.”

Malone nodded, silently this time. He had the sudden feeling that Dr. O’Connor’s flow of words had broken itself up into a vast sea of alphabet soup, and that he, Malone, was occupied in drowning in it.

“However,” Dr. O’Connor said, breaking what was left of Malone’s train of thought, “young Charlie died soon thereafter, and we decided to go on checking the machine. It was during this period that we found someone else reading the minds of our test subjects — sometimes for a few seconds, sometimes for several minutes.”

“Aha,” Malone said. Things were beginning to make sense again. Someone else. That, of course, was the spy.

“I found,” Dr. O’Connor said, “on interrogating the subjects more closely, that they were, in effect, thinking on two levels. They were reading the book mechanically, noting the words and sense, but simply shuttling the material directly into their memories without actually thinking about it. The actual thinking portions of their minds were concentrating on aspects of Project Isle.”

There was a little silence.

“In other words,” Malone said, “someone was spying on them for information about Project Isle?”

“Precisely,” Dr. O’Connor said with a frosty, teacher-to-student smile. “And whoever it was had a much higher concentration time than Charlie had ever attained. He seems to be able to retain contact as long as he can find useful information flowing in the mind being read.”

“Wait a minute,” Malone said. “Wait a minute. If this spy is so clever, how come he didn’t read your mind?”

“It is very likely that he has,” O’Connor said. “What does that have to do with it?”

“Well,” Malone said, “if he knows you and your group are working on telepathy and can detect what he’s doing, why didn’t he just hold off on the minds of those geniuses when they were being tested in your machine?”

Dr. O’Connor frowned. “I’m afraid that I can’t be sure,” he said, and it was clear from his tone that, if Dr. Thomas O’Connor wasn’t sure, no one in the entire world was, had been, or ever would be. “I do have a theory, however,” he said, brightening up a trifle.

Malone waited patiently.

“He must know our limitations,” Dr. O’Connor said at last. “He must be perfectly well aware that there’s not a single thing we can do about him. He must know that we can neither find nor stop him. Why should he worry? He can afford to ignore us — or even bait us. We’re helpless, and he knows it.”

That, Malone thought, was about the most cheerless thought he had heard in some time.

“You mentioned that you had an insulated room,” the FBI agent said after a while. “Couldn’t you let your men think in there?”

Dr. O’Connor sighed. “The room is shielded against magnetic fields and electro-magnetic radiation. It is perfectly transparent to psionic phenomena, just as it is to gravitational fields.”