"I see," Lentz observed politely. "What element are you examining now"

Harper told him. "But it's not a case of examining one element - we've finished Isotope II of this element with negative results. Our schedule calls next for running the same test on Isotope V. Like this." He hauled out a lead capsule, and showed the label to Lentz. He hurried away to the shield around the target of the betatron, left open by Erickson. Lentz saw that he had opened the capsule, and was performing some operation on it with 'a long pair of tongs in a gingerly manner, having first lowered his helmet. Then he closed and clamped the target shield.

"Okay, Gus?" he called out. "Ready to roll?"

"Yeah, I guess so," Erickson assured him, coming around from behind the ponderous apparatus, and rejoining them. They crowded behind a thick metal and concrete shield that cut them off from direct sight of the set up.

"Will I need to put - on armor?" inquired Lentz.

"No," Erickson reassured him, "we wear it because we are around the stuff day in and day out. You just stay behind the shield and you'll be all right."

Erickson glanced at Harper, who nodded, and fixed his, eyes on a panel of instruments mounted behind the shield. Lentz saw Erickson press a push button at the top of the board, then heard a series of relays click on the far side of the shield. There was a short moment of silence.

The floor slapped his feet like some incredible bastinado. The concussion that beat on his ears was so intense that it paralyzed the auditory nerve almost before it could be recorded as sound. The air - conducted concussion wave flailed every inch of his body with a single, stinging, numbing blow. As he picked himself up, he found he was trembling uncontrollably and realized, for the first time, that he was getting old.

Harper was seated on the floor and had commenced to bleed from the nose. Erickson had gotten up, his cheek was cut. He touched a hand to the wound, then stood there, regarding the blood on his fingers with a puzzled expression on his face.

"Are you hurt?" Lentz inquired inanely. "What happened?"

Harper cut in. "Gus, we've done it! We've done it! Isotope Five has turned the trick!"

Erickson looked still more bemused. "Five?" he said stupidly, " - but that wasn't Five, that was Isotope IL I put it in myself."

"You put it in? I put it in! It was Five, I tell you!"

They stood staring at each other, still confused by the explosion, and each a little annoyed at the boneheaded stupidity the other displayed in the face of the obvious. Lentz diffidently interceded.

"Wait a minute, boys," he suggested, "maybe there's a reason - Gus, you placed a quantity of the second isotope in the receiver?"

"Why, yes, certainly. I wasn't satisfied with the last run, and I wanted to check it."

Lentz nodded. "It's my fault, gentlemen," he admitted ruefully. "I came in, disturbed your routine, and both of you charged the receiver. I know Harper did, for I saw him do it with Isotope V. I'm sorry."

Understanding broke over Harper's face, and he slapped the older man on the shoulder. "Don't be sorry," he laughed; "you can come around to our lab and help us make mistakes anytime you feel in the mood - Can't he, Gus? This is the answer, Doctor Lentz, this is it!"

"But," the psychiatrist pointed out, "you don't know which isotope blew up."

"Nor care," Harper supplemented. "Maybe it was both, taken together. But we will know - this business is cracked now; we'll soon have it open." He gazed happily around at the wreckage.

In spite of Superintendent King's anxiety, Lentz refused to be hurried in passing judgment on the situation. Consequently, when be did present himself at King's office, and announced that he was ready to report, King was pleasantly surprised as well as relieved. "Well, I'm delighted," he said. "Sit down, doctor, sit down. Have a cigar. What do we do about it?"

But Lentz stuck to his perennial cigarette, and refused to be hurried. "I must have some information first: how important," he demanded, "is the power from your plant?"

King understood the implication at once. "If you are thinking about shutting down - the plant for more than a limited period, it can't be done."

"Why not? If the figures supplied me are correct, your power output is less than thirteen percent of the total power used in the country."

"Yes, that is true, but we also supply another thirteen percent second hand through the plutonium we breed here - and you haven't analyzed the items that make up the balance. A lot of it is domestic power which householders get from sunscreens located on their roofs. Another big slice is power for the moving roadways - that's sunpower again. The portion we provide here directly or indirectly is the main power source for most of the heavy industries - steel, plastics, lithics, all kinds of manufacturing and processing. You might as well cut the heart out of a man - "

"But the food industry isn't basically dependent on you?" Lentz persisted.

"No ... Food isn't basically a power industry though we do supply a certain percentage of the power used in processing. I see your point, and will go on, concede that transportation, that is to say, distribution food, could get along without us. But good heavens, Doctor, you can't stop atomic power without causing the biggest panic this country has ever seen. It's the keystone our whole industrial system."

"The country has lived through panics before, and we got past the oil shortage safely."

"Yes because sunpower and atomic power had to take the place of oil. You don't realize what would mean, Doctor. It would be worse than a war; in system like ours, one thing depends on another. If you cut off the heavy industries all at once, everything else stops too."

"Nevertheless, you had better dump the pile." The uranium in the pile was molten, its temperature bell greater than twenty - four hundred degrees centigrade. The pile could be dumped into a group of small containers when it was desired to shut it down. The mass into one container would be too small to maintain progressive atomic disintegration.

Icing glanced involuntarily at the glass - enclosed relay mounted on his office wall, by which he, as well as the engineer on duty, could dump the pile, if need be. "But couldn't do that ... or rather, if I did, the plant wouldn't stay shut down. The directors would simply replace me with someone who would operate it."

"You're right, of course." Lentz silently considered the situation for some time, then said, "Superintendent, will you order a car to fly me back to Chicago?"

"You're going, doctor?"

"Yes." He took the cigarette holder from his face, and, for once, the smile of Olympian detachment was gone completely. His entire manner was sober, even tragic.

"Short of shutting down the plant, there is no solution to your problem - none whatsoever!"

"I owe you a full explanation," he continued, presently.

"You are confronted here with recurring instances of situational psychoneurosis. Roughly, the symptoms manifest themselves as anxiety neurosis, or some form of hysteria.

The partial amnesia of your secretary, Steinke, is a good example of the latter. He might be cured with shock technique, but it would hardly be a kindness, as he has achieved a stable adjustment which puts him beyond the reach of the strain he could not stand.

"That other young fellow, Harper, whose blowup was the immediate cause of you sending for me, is an anxiety case. When the cause of the anxiety was eliminated from his matrix, he at once regained full sanity. But keep a close watch on his friend, Erickson - "However, it is the cause, and prevention, of situational psychoneurosis we are concerned with here, rather than the forms in which it is manifested. In plain language, psychoneurosis situational simply refers to the common fact that, if you put a man in a situation that worries him more than he can stand, in time he blows up, one way or another.