Pell said, "Ben, get Kalender on my visor, will you?" He nodded at Ridgeley, turned, and disappeared through the door behind him. By the time he came back, Kalender's heavy, hard face was on the screen.

  The courier took a cylindrical metal case from his pocket. Robert Cameron, behind Pell, ignored it. The director went straight to the televisor and faced Kalender.

  "Oh—Cameron," the Secretary of War said. "Did you get that—"

  Cameron said, "Listen. All messages and contacts are to be filtered through my aide, Seth Pell, until further notice. I want nothing delivered directly to me. Hereafter all calls to me must reach Pell first. Including GHQ and priority calls."

  "What?" Kalender was taken aback. His strong jaw thrust forward. "Yes, yes," he said impatiently. "But I want to talk to you. My courier—"

  "I haven't talked to him. He must deal with Pell."

  Kalender snapped; "This is official business, Cameron—and priority! I don't want this handled by subordinates! I want—"

  "Mr. Secretary," Cameron said quietly. "Listen to me. I'm not under GHQ. I'm running the Department of Psychometrics my way, and I don't permit my authority here to be questioned. If I wish to use Seth Pell as a filter, that is my affair. Until the government gives you more authority than you've got now, you'll allow me to handle my own business in my own way. That's all!"

  He snapped the switch on the apoplectic Secretary of War and turned to his office. The courier stepped forward.

  "Mr. Cameron—"

  Cameron gave him a cold stare. "Did you hear what I told Mr. Kalender?"

  Ridgeley said, "I've got my orders." He held out the metal case.

  The director hesitated. Then he took it. "All right," he said. "You've done your job."

  He handed the case to Pell and walked back into his office. The door closed softly.

  Pell tapped the metal cylinder against his knuckles. He waited, watching Ridgeley.

  "Well," the courier said, "I gave it to the director, anyhow." His eyes met DuBrose's briefly; then he saluted casually and went out.

  Pell tossed the cylinder on the desk. "Nice going," he said. "Lucky the chief backed me up."

  DuBrose touched the vibropistol with an exploratory finger. "I ... did the chief—"

  "It's all right." Pell smiled. "We've time to work on the problem now. I gave our director the works—a complete quick mnemonic treatment. He doesn't remember anything that's happened today. I gave him some phony memories instead. Now we can let him have the problem without the responsibility—if we can figure out how to do that."

  "You didn't rouse his suspicions?"

  "The chief trusts me. Completely. I told him I wanted to be a filter for a while, and not to ask me why. He'll wonder, of course, but he can't guess the right answer. I've wiped out the dangerous memories."

  "Completely?"

  "Completely."

  -

  Cameron opened the window and watched the red darkness pulse and shift. A vague memory troubled him, but not too much. It was simply part of this thing that had come on him—the thing he had to fight out by himself. There must be a reason. There had to be. If he submitted himself to psychiatric examination, he'd ... no. That wasn't the way. Visual and auditory—and tactile—hallucinations ...

  That dim memory came back. It was impossible to place its sequence in the day's events—a fairly dull and ordinary day. He hadn't budged from the office, there had been few callers—but this memory, like the doorknob and the clock and the smiling altitude gauge, probed with soft insistence into his mind.

  A man floating in midair.

  Hallucination.

  -

  IV.

  "The chief's gone home," DuBrose said.

  "Fair enough." Pell spread papers on his desk.

  "Shouldn't one of us—"

  The aide glanced sharply at DuBrose. "Relax, Ben," he said lightly. "Hypertension's setting in. The chief won't receive any calls. He'll have 'em routed to me. Mm-m—" He hesitated. "Look. Take these cards and alphabetize 'em while we talk. Or else have some Deep Sleep."

  DuBrose accepted the cards, shuffling them automatically into sequence. "Sorry," he said, "this thing's got me a bit, I guess."

  Pell's white hair glistened as he bent forward over the charts. "Why should it?"

  "I don't know. Empathy—"

  "Orbs," Pell said, "I could be as jittery as you if I wanted to. But I've studied history and literature. And architecture, and a lot of things. Just to balance this psycho work. There's a lot more perfection in a Doric column than in you."

  "Yeah. But I can build a Doric column."

  "You can also build a backhouse. That's the trouble. You're as likely to do one as the other." He chuckled. " 'I do not like the human race ... I do not like its silly face.' "

  "What's that?"

  "A guy named Nash. You never heard of him. The thing is, I'm part misogynist, Ben. If somebody wants me to like him, he's got to prove he's worth liking. Few people do."

  "Oh, philosophy," DuBrose growled, dropping a card. "What's this? Palate deformation developing at twenty with—"

  "Group of cases I've been investigating," Pell said. "Academic value only, I'm afraid. No, it isn't philosophy; I just can't get excited over anything that threatens people in the aggregate. Humans aren't selective. They lost selectivity when they gave up instinct for intelligence. And so far they haven't learned to discipline their creative powers. A bird will build a nest that's a beautiful piece of engineering."

  "Dead end."

  "I'm not infatuated with birds either," Pell remarked. "They're too reptilian for my taste. But people—in fifty thousand years or three times that time, they may have learned the art of selectivity. They'll be worth knowing—all of them. At present genus homo is struggling up through the mire, and I'm fastidious."

  "Proving what?" DuBrose asked, irritated.

  "Proving my egotism," Pell laughed. "And explaining why I'm not hot and bothered over this particular danger." But, DuBrose thought, it didn't explain why Pell seemed so unconcerned about the danger threatening the director. Cameron was Pell's closest friend; there was a warm affection between the two men. It was something else in the aide's mind, a latent strength, a steel discipline, that enabled him to keep his balance.

  DuBrose didn't know Pell. He admired and trusted him, but had never tried to encroach on a certain deep restraint that Pell kept buried, under his casual flippancy. Often he wondered. There were rumors, scandalous even in these amoral days, about Seth Pell's private life—

  "Uh-huh," the aide said. "Quite a problem. Everybody who's worked on this equation is either showing signs of strain or going nuts. Unless—here's a factor—unless they could delegate the responsibility. The enemy's been dropping bombs that penetrate force-fields. A few have exploded. Most haven't. Apparently the hookup's impossible. There's one gadget that can't possibly work on the same circuit with another gadget. Twelve men in various fields have already gone insane. Two with suicidal tendencies have committed suicide. Somebody named Pastor—physicist—says he'll have the equation solved within a few days. No way of checking that at the moment. And so on, and so on. We'll have to make some personal interviews. Our job is to gather the data and correlate it. Including the fact that part of the equation can nullify gravity."

  DuBrose had finished alphabetizing the cards. He flipped them idly.

  "How can we present the problem to the chief?"

  "Well—he mustn't realize its importance. I think the best way is to bury it. Handle the whole affair casually. But not give him the equation. He's too good a general scientist to be trusted with that. If he tried to solve it himself ... and it seems to have some sort of fascination. No, we've got to gather all the information that's pertinent, make sure it's innocuous, and hand it over to the chief. That means leg work."

  "Can we handle it that way? Isn't there a danger of emasculating the vital factors so much that—"

  Pell said, "We've got to find out exactly why technicians go crazy when they try to solve the equation. And the chief has to think of somebody who can solve it."

  He stood up. "That's enough for now. Let's wind up the day." He tossed the papers into a drawer and made adjustments. A dome of icy white light sprang into existence around the desk.

  DuBrose said, "Force-fields may not be so safe any more, if the enemy can drop bombs through them."

  "I set the incendiary, too," Pell said. "But who'd want to steal that equation? The enemy's got it already." He went into the examination room, DuBrose following. The boy still lay asleep on the padded table, his eyes closed, his breathing even.

  -

  "Who is he?" DuBrose asked.

  "Name's Billy Van Ness. Typical case—one of that group on the cards you were juggling. Delayed puberty, age twenty-two now, sudden physical and mental changes started two months ago. Only constant is the fact that all the cases were born within a radius of two miles from a Dud."

  "Radiation affecting the genes of the parents?" DuBrose was picturing the silvery, tattered dome on the arid hillside.

  "Could be."

  "Enemy?"

  "A weapon that didn't work, then. Only about forty cases in all. It's odd; they were all perfectly normal up to two months ago—except for delayed maturation. Then they matured and some curious physiological changes set in. Deformation of the palate ... but it's the mental metamorphoses which are more interesting. They never open their eyes—a familiar enough symptom. Recognize it?"

  "Naturally."

  "But—"

  "Wait a minute," DuBrose said. "That boy could see. He walked around a chair that was in his way."

  "A little trick they have," Pell smiled. "ESP for all I know. They never bump into anything when they walk about—which is seldom—but they never go in a straight line. A twisting, erratic pattern always, as though they're walking around things that aren't there as well as things that are."

  "Balance distortion?"

  "No, they're steady. They just walk as though they're threading a path through a roomful of eggs. What excited this boy?"

  DuBrose made a few guesses.

  "It's unusual," Pell said. "They seldom rouse from their passivity unless they're near a Dud. That seems to excite them. They make that funny noise. Unpleasant, isn't it?"

  "Any prognosis yet, Seth?"

  Pell shook his head. "I'm going to try mnemonic probing. If nothing else works. I may be able to throw this boy's mind back to his more normal past. Well, let's have those cards." He tossed them on a table and rang for an attendant. "Billy can stay in the infirmary tonight—private room. Get your cloak. Ben. We're going out."

  DuBrose said, "Any equipment—"

  Pell chuckled. "Not for this therapeutic work, brother. We're going to extrovert for a few hours—but good. You've got a bad case of hypertension. Deep Sleep won't cure it. If I told you to go out and eat Pix, you'd do it, but you'd still feel subconscious anxiety. This way you'll be able to relax, because I'm your superior, and the responsibility's mine."

  "But ... look, Seth—"

  "You're going through the mill tonight," Pell said. "Tomorrow we'll go crazy together."

  -

  Only a helicopter could have landed on this outcrop of the Rockies. A drill-press had run wild across the sky: the rarefied atmosphere made even low-magnitude stars brilliant. The path of the Milky Way splashed its cataract toward the Wyoming horizon eastward, and the frigid wind made DuBrose's jaw muscles tighten. Then the force-field lifted again, blotting out the sky in a curdled dome of silently crackling light.

  The house under the field looked like a chalet, but those steeply sloping roofs were functional in a region where the snowfall was measured in yards. It wasn't snowing now; bare, brittle ground crunched under DuBrose's feet. He went on with Pell toward the porch and presently was standing in a huge room that might have been furnished by a color-blind man. A dozen periods of furniture were represented; a Louis XIV sofa sat under a Gobelin tapestry, and the tapering sleekness of Brancusi's "Bird in Space" perched incongruously on a Victorian marble-topped pedestal. Oriental rugs clashed violently with bearskins on the floor and trophy heads on the wall. One whole side of the room was a segmented projection screen. Beneath it was a Fairyland box and control panel, one of the most complicated DuBrose had ever seen.

  "Wonder if Pastor furnished this place himself?" DuBrose muttered.

  "Sure," a voice behind him said. "Just the way I wanted it. It scares people sometimes. Make your landing all right? The thermals are tricky around here."

  "We managed," Pell said. DuBrose was staring at the gnomish little man, with his wrinkled nutcracker face. And Dr. Emil Pastor stared back, blinking through heavy lenses.

  "Oh, it's you," he said. "I never did catch your name."

  "DuBrose. Ben DuBrose. Dr. Pastor and I met at the sanatorium, Seth—he was examining that patient, M-204. The one who floated."

  "Floated," Pastor said, blowing out his cheeks expressively. "You don't know half of it. I found out what part of the equation he was working on. Lovely stuff, pure symbolic logic, except for one thing. Two things, rather. If you neutralize gravity completely, centrifugal force will shoot you out in space at a tangent. Right? But M-204 just floated. According to his figures—based on that equation—the trick's theoretically possible. All you have to do is utilize the arbitrary values the equation assigns to two symbols—orbital velocity of the earth and the power necessary to lift a body out of the earth's gravitational influence."

  "Arbitrary values?" DuBrose asked.

  "Sure. They're really constants. 66,600 m.p.h. for the first, 6,000,000 kilogram-meters for the second. The equation says it only takes 10 kilometers to get away from gravity, and the first constant can be ignored. It's zero. The earth doesn't revolve at all."

  "What?" Pell said.

  Pastor made a significant gesture. "I know. M-204 is insane. But his insanity is based on something peculiar. He thinks he can float because the earth doesn't revolve. And—he floats. Nevertheless it moves!"

  The aide said, "What about those 10 kilometers? Energy—"

  Pastor nodded. "That, too. Energy has to be expended constantly to maintain a balance like that—antigravity. Unless you have enough orbital velocity to keep moving, like the moon. But M-204 doesn't expend energy, does he? Or does he?"

  "Your instruments went haywire, you said," DuBrose suggested.

  "Which is significant," the little physicist agreed. "Perhaps from where M-204's sitting, the earth doesn't revolve. But my instruments aren't able to register that; they were built on an earth that does revolve." He laughed shortly. "I'm so immersed in this business that I've forgotten my manners. Take off your cloaks. Drink? Deep Sleep?"

  DuBrose demagnetized his throat-fastener and tossed his cloak toward a rack that caught it deftly. "Thanks, no. We won't keep you long. You're—"

  "I'd have solved the equation before this," Pastor said, "if the big shots hadn't moved me out of Low Manhattan. They found out some bombs were exploding and figured I might wreck the cave. So I came up here. If I do detonate, the force-field will limit the casualties."

  Pell said, "Those bombs could penetrate force-fields, couldn't they?"

  "They could indeed. Come in here." Pastor herded them into a cluttered laboratory, much of it singularly unorthodox and jerry-built. He searched a messy table for a photostat blueprint. "Here's a diagram of the bomb's mechanism. Know anything about electronics?"

  "Very little," Pell said, while DuBrose merely shook his head.

  "Oh. Well. Anyhow, see this tricky business? It'll work on one type of circuit, but not on another. This other gadget will work on the other type of circuit only. But they're both functioning perfectly on the same circuit. We've tried reversing them, we've tried standing on our heads and looking cross-eyed, but the fact remains. Two mutually incompatible elements are functioning beautifully together. It can't be. But it is."

  Pell stared at the diagram. Pastor said, "What do you think of that?"

  "I think it's tough on the engineers who had to figure out how and why the bombs got through force-fields."

  The physicist said, "The equation, as far as I can tell yet, is founded on something like variable logic. It's full of mutually incompatible basics."

  "Two and two make five?" Du Brose said.

  "Two and whee make diddle plus," Pastor corrected. "It can't be expressed in basic English. A semantics expert would give up in disgust. It says here"—he indicated a paper—"that a free-falling body drops at the rate of five hundred feet a second. Later on in the equation that body is dropping at nine inches a second. And that's a basic!"