half the doctors we have."

Then he heard the deep, gruff voice of Dr. Blair Gaddon half laugh.

"Thanks a lot, Fenwick. You've taken a load off my mind. Goodbye, Miss Drake."

He heard Joan reply and then saw Dr. Fenwick usher the physicist out into the hall.

Trent rose as the two men approached.

"Why, hello, Trent," Dr. Fenwick said.

Trent nodded at the tall, white-coated figure of the famous gland specialist.

"Afternoon, doctor."

Fenwick smiled at him. "Don't tell me you're waiting to see me?"

Fred shook his head. "Not exactly. I was waiting to see Dr. Gaddon though. I was on my way out to the Proving Grounds and I happened to stop by and talk to Miss Drake." He turned to the physicist, a bulky man with firm, hard features, who moved his large body with an almost cat-like grace.

"I hope you don't mind, Dr. Gaddon. Possibly I can give you a lift back out to the Base. I'm covering the launching for my paper."

Gaddon smiled at him. "But of course I don't mind. And I'll take you up on that offer. It'll save me a trip back to town to take one of the staff cars."

The words had a friendly note to them, as did the smile on Gaddon's face. And yet, somehow, Fred Trent found that he did not like this man. It was nothing he could put his finger on, nothing he could rationalize, unless it was the coldly calculating look in the scientist's eyes.

"That's fine, doctor," Trent replied. "Shall we go?"

He turned and said good-bye to Fenwick and passed a smiling glance at the girl. He could see her blush slightly as Fenwick caught the glance and laughed. Then they were out of the house and Trent led the way to his car.

Inside, he started the motor and drove away. Beside him, Gaddon lit a cigar and blew a long plume of smoke through the open window.

"You said you wanted to talk to me, Trent?"

Fred nodded. "That's right, doctor. I'm writing up the rocket experiment for my paper, and I thought maybe you could give me a few details of interest." He paused for a moment, then asked: "Would it be too personal to ask if your visit to Dr. Fenwick had anything to do with the coming experiment?"

Gaddon shot a quick glance at him.

"Why do you ask that?"

Fred Trent shrugged. "It was just a thought. I heard Dr. Fenwick talking about your heart, but you look pretty healthy to me, so I thought maybe it was because Fenwick is a gland specialist and you might be talking to him about examining the cat after the rocket returns ..."

Gaddon laughed roughly. "A mighty clever reasoning, Trent, but not quite correct. The fact is, I was seeing the doctor for personal reasons. Just a physical checkup. It had nothing to do with the rocket experiment or the effect of the cosmic rays on the animal we're including in the experiment."

"It was just a thought, doctor," Trent replied, as he moved the coupe out on the open highway away from Tucson and toward the Rocket Proving Grounds on the desert flats in the distance.

"So now that we've disposed of that, what else would you like to know?" Gaddon asked him, a peculiar edge to his voice that Trent did not miss.

"Well, I would like to get a first hand bit of information on just exactly what you plan to prove with this experiment. If I'm correct, Dr. Mathieson, the head of the project, contends that cosmic rays may be lethal, and this experiment is to prove his point."

The physicist snorted. "It is no secret that Mathieson and myself disagree violently on that subject."

Trent's eyebrows raised. "Is that so? I wasn't aware of it?"

Gaddon paused, seeing that his words had slipped out too freely. Finally he said, "What I meant to say, Trent, is that up until now it has not been a public issue of disagreement. And I would prefer to have it remain a private matter until after the experiment."

"I see," Trent mused. "You have my word that I won't print anything you say without your permission. But just what is the difference of opinion between you and Mathieson?"

Gaddon took a long pull at his cigar and waited a few moments before replying. It was apparent to Trent that he was debating continuing the subject with a newspaperman. But Trent had gauged the man correctly. There was a flair of vanity in Gaddon that dated back to his English ancestry. Trent remembered that Gaddon, quite a figure in English scientific circles, had created a stir when he had come over to the United States to assist in rocket research at the Arizona proving grounds. It seemed that Gaddon had not wanted to take a back seat to the famed American scientist, Mathieson. It had made a few gossip columns in the newspapers before Washington put an official clamp on the matter.

Now, as Trent waited for the Englishman to reply, he could almost sense the thoughts that were going through Gaddon's mind. The Englishman was debating whether to take an open stand against the viewpoints of his American colleague. But Trent felt that the British stubbornness in the man would make him reveal his own theories. Especially since Trent had already promised not to print anything without Gaddon's permission. That would give him an opportunity to gloat safely, should his own ideas be proven correct.

"Very well, Trent, I'll take you at your professional word to keep this matter confidential. But if what I contend is correct, you'll have a big story to tell."

Trent waited expectantly, not wanting to break the Englishman's train of thought.

"The fact is, Trent, that Mathieson is all wrong. To go even further, most of your American scientists don't have the haziest idea of exactly what the cosmic rays are. We in Britain have made quite exhaustive studies of the phenomena."

Trent didn't bother to argue with him. He only nodded his head. It would have been silly, he knew, to contradict Gaddon, to tell him that the English didn't know a thing more about the cosmic rays than the American scientists, that American science had made, and was continually making, exhaustive research into that scientific field of study on as great if not more so a scale than Britain could possibly achieve. It was only Gaddon's vanity talking, Trent knew, so he let him put in the barb of ridicule, waiting.

"I was sent over here, as you may know, to aid in the current experiment. To formulate it as a matter of fact. This test is being conducted to determine just what effect cosmic rays will have on a living organism. As I said, Mathieson, and your other scientists are of the opinion that the rays are lethal. That they will destroy life. In effect, that they are death rays.

"But I contend that they are wrong. What would you say if I told you that cosmic rays are the very source of life and energy in the universe?"

Trent whistled judiciously, and noted that Gaddon's face smiled at the apparent surprise Trent evinced.

"You find that a startling statement?"

Trent nodded. "I'd say that it sounded like the beginning of a very interesting theory."

"And you would be right," Gaddon replied, warming to his subject. "It is my contention that the cosmic rays will prove to be the fountain of youth that men have sought through the ages. That they will react on the glands of a living creature and produce immortality.

"Now take your choice. Whose theory would you rather believe? Mathieson's idiotic claims of a death ray, or mine as a source of the utmost benefit to science?"

Trent took a moment before replying. When he did so, he spoke with tact, and also with the feeling that his trip to Fenwick's office had proven very valuable. For there was a story here. A big story.

"I'd say, doctor, that I'd like to believe your theory was correct. But isn't it a little premature to be so definite about it?"

Gaddon snorted. "No more premature than Mathieson's. And I'll tell you something else, Trent. You may not realize it, but you're about to take part in what may be