And it was dangerous to fill with unquestioning followers of the strongest man a world in which General George Hamilton controlled the United States. He was in his fourth term as president as the first great group of Gory System children came to maturity. Fiercely and sincerely he believed in the subjugation of the many to the State, and this new generation found in him an almost divinely inspired leader.

General George dreamed of a United World in which all races lived in blind obedience and willing sacrifice for the common good. And he was a man to make his dreams come true. Of course, he ad-mitted, there would be opposition at first. There might be b.l.o.o.d.y wars, but in his magnificent dreams he believed sincerely that 110 price could be too high, that the end justified any means necessary to achieve it. And it seemed like the cooperation of Heaven itself to find almost an entire generation coming into adulthood ready to ac-cept his leadership implicitly.

He understood why. It was no secret now what effect the Cory Sys- tern had upon the children it produced. They would follow the strongest leader with blind faith. But upon this one generation of fol-lowers General George knew he could build a future that would live after him in the magnificent fulfillment of his most magnificent dreams. For a war lord needs a nation of soldiers, a great crop of boy babies to grow into armies, and surprisingly few saw the real motive behind General George's constant cry for boys, boys, boys-huge fam-ilies of them. Fathers of many sons were feted and rewarded. Every-body knew there was the certainty of war behind this constant appeal for familiesof sons, but comparatively few realized that since the best way to be sure of boys was the use of the Cory System, the whole new generation would be blind followers of the strongest leader, just as their fathers were. Perhaps the Cory System might have died of its own great weakness, its one flaw, had not General George so pur-posefully demanded sons of his followers.

General George died before the first great war was over. His last words, gasped in the bursting tumult of a bomb raid over Washing-ton were, "Carry on-unite the world!" And his vice-president and second in command, Phillip Spaulcling, was ready to s.n.a.t.c.h up the falling torch and light the world to union.

Half the United States lay in smoking ruins before the Great War ended. But General George had builded well upon that most endur-ing of all foundations-the faith of men. "Be fruitful and multiply," was a command his followers had obeyed implicitly, and Spaulding had mighty resources of human brawn and human obedience to draw upon.

The great general had died gladly for his dream, and he had not died in vain. Half the world was united under his starry banners within a decade after his death; the United World of his vision came into being less than fifty years later.

With peace and blind faith and prosperity, Science City indeed came into its own. And because a taste of power had made the Lead-ers hungry, the eyes of the City turned upward toward starry s.p.a.ce. During the command of the Fourth Leader after the immortal Gen-eral George, the first successful s.p.a.ce voyage was achieved. The first living man stood knee-deep in the dead pumice dust of the moon and a mighty forward stride for mankind was recorded.

It was only a step. Mars came next, three generations later. After a brief and b.l.o.o.d.y war, its decadent inhabitants surrendered and the Seventh Leader began to have giddily intoxicating dreams of a United Solar System- Time telescoped by. Generation melted into generation in chang-ing tides over a world population that seemed unaltering in its by now age-old uniforms of George Blue. And in a sense they were unaltering. Mankind was fixed in a mold-a good enough mold for the military life of the U. W.-the United World. The Cory System had long ago become compulsory, and men and women were produced exactly in the ratio that the Leaders decreed. But it was significant that the Leader cla.s.s came into the world in the old haphazard fashion of the days before the legendary Dr. Cory's discovery.

The name of Cory was a proud one. It had long been a tradition in that famous family that the founder's great System should not be used among themselves. They were high among the Leader cla.s.s. Sev-eral of the Leaders had borne the surname of Cory, though the office of course was not hereditary, but pa.s.sed after rigid training and strict examination to the most eligible of the Candidates Cla.s.s when an old Leader pa.s.sed his prime.

And among the mighty Corys, family resemblance was strong. Gen-erations saw the inevitable dilution of the original strain, but stub-bornly through the years the Gory features came and went. Some-times only the darkly blond hair of the first great Bill, sometimes the violet eyes which his pretty Marta had bequeathed her son, sometimes the very face of young Bill Jr. himself, that had roused an ache of pride and love in his father's heart whenever he saw those beloved fea-tures.

The Gory eyes looked now upon two worlds, triumphantly regimented to the last tiny detail. Mankind was proving his suprem-acy over himself-over his weaknesses and his sentimental, selfish desires for personal happiness as opposed to the great common good. Few succ.u.mbed to such shameful yearnings, but when they did, every man was a spy against his neighbor, as stern as the Leader himself in crushing these threats to the U. W.'s strength. It should be the indi-vidual's holiest and most mystically pa.s.sionate dream to sacrifice his happiness for the Leader and the U. W., and the Leader and the United World lived for the sole purpose of seeing that he did.

Marvelous was the progress of mankind. The elements had~ long since been conquered; the atom had yielded up its incalculable power in the harness of the machines, s.p.a.ce itself was a highway for the vehi-cles of the U. W.

Under the blue-black skies of Mars, mankind's checkerboard cities patterned the hot red soil; under thesoft gray clouds of Venus, those roofed and checkered cities spread from a common center through jungles steaming in more than tropic heat. Many-mooned Jupiter was drawing the covetous eyes of the Leaders in their sky-high cities of gla.s.s and steel.

And moving through these patterned cities upon three worlds, the followers of the Leader went about their ways, resolute, unfaltering, their faces set in one pattern of determination.

It was not a happy pattern. There was little laughter here; the only emotion upon the serious faces, aside from the shadow of that same exaltation that blazed in the Leader's eyes, was a subtle furtiveness, a sidelong quality that by intuition seemed to distrust its neighbors. Bill recognized it. Every man's duty was to sacrifice for the Cause not only his personal desires and happiness, but his personal honor as well; he must keep relentlessly alert for traitorous weakness in his friends, his a.s.sociates, his own family.

Mistily the panorama of the centuries began to melt into itself, to fade, while behind it a blue-eyed face, helmed in blue steel, took form to smile straight into Bill's eyes. A tense, expectant smile, supremely confident.

Bill sat back and breathed deeply, avoiding for a moment the proudly smiling face of his son.

"I'm-there!" he was thinking. "That was me being born again and again, working with all my heart to crush out human happiness- But there was Sue, too, generations of her-yes, and of me-working just as sincerely toward an opposite goal, a world without war. Either way they've got me. If I don't finish my work, the world unbalances toward matriarchy; if I do, mankind turns into a machine. It's bad. Either way it's bad-"

"The doctor is almost overwhelmed at the realization of his own greatness," Dunn's voice murmured from the window into the future. Bill recognized it for a sort of apology, and sat up with an effort to meet the pride-bright eyes of the boy who one day might be his son. There was nothing but happy expectancy of praise on the boy's face, but Dunn must have read a little doubt in Bill's, for he said heavily, as if to overwhelm that doubt: "We build toward one common end, all of us-we have no thought for any smaller purpose than the conquest of the Solar System for the mighty race of man! And this great purpose is yours no less than ours, Dr. Cory."

"Manpower is what counts, you know, sir." Young Billy's voice took up the tale as Dunn's died. "We've got tremendous reserves, and we're piling up still more. Lots of room yet on Mars to fill up, and Venus is almost untouched yet. And after that, we'll breed men and women adapted to Jupiter's gravity, perhaps . . . oh, there'll be no end to our power, sir! We'll go on and on- Who knows? There may come a day when we're a United Universe!"

For an instant, hearing the young voice shake with eagerness, Bill doubted his own doubtfulness. The mighty race of man! And he was part of it, living in this far-off future no less than he lived now in the flesh, in the burning ardor of this iron-faced boy. For a moment he forgot to be amazed and incredulous that he stood in the Twenty-third Century and looked as if through a window into the Thirtieth, talking with the unborn descendant of his yet unconceived son. For this moment it was all accomplished reality, a very magnificent and blood-stirring present achieved directly through his own efforts.

"Father. . . father!" The voice was sweet and high in the core of his brain. And memory came back in an overwhelming rush that for an instant drowned out everything but a father's awareness of special love for a favorite daughter.

"Yes, Susan - - . yes, dear." He murmured it aloud, swinging around toward the cube that housed his other future. Sue leaned for-ward upon her knees among the myrtle leaves, her brown eyes wide and a little frightened upon his. There was a crease between her winged brows that dented Bill's own forehead as he faced her. For a moment it was almost as if each of them looked into a mirror which reflected the features of the other, identical in nearly every detail. Then Sallie's smile dimpled the cheeks of her far-descended daughter, and Sue laughed a small, uneasy laugh."What is it, father? Is something wrong?"

He opened his lips to speak-but what could he say? What could he possibly say to her, who did not even dream that her own time was anything but inevitable? How could he explain to a living, warmly breathing woman that she did not exist, might never exist?

He stared at her unhappily, groping for words he could not find. But before he spoke- "Dr. Cory, sir- Is anything wrong?" He turned back to Billy with a harried crease between his brows and then stared wildly from one face to the other. How could they help hearing one another? But ob-viously Billy, from his window into the present, saw simply the cube that held Sallie's immortal smile, while Sue, from hers, looked upon Marta's changeless face. It seemed to Bill that the boy and the girl had spoken in voices almost identical, using words nearly the same, though neither was aware of the other. How could they be? They could not even exist simultaneously in the same world. He might have one of these beloved children or the other; not both. Equally beloved children, between whom he must choose-and how could he choose?

"Father-" said Sue on a rising inflection of alarm. "There is some-thing wrong. I. . . feel it in your mind- Oh, what is it, father?"

Bill sat speechless, staring from one face to the other of these mutu-ally exclusive children. Here they stood, with their worlds behind them, looking anxiously at him with the same little crease between the brows of each. And he could not even speak to either without con-vincing the other he was a madman talking to empty air. He wanted insanely to laugh. It was a deadlock beyond all solution. Yet he must answer them-he must make his choice- As he sat there groping in vain for words, a curious awareness began to take shape in his mind. How strange it was that these two should have been the ones to reach him, out of all the generations behind each that had been searching the past. And why had they established contact at so nearly the same time, when they had all his life span to grope through, hunting him for such different reasons, in such different ways? There was more than accident here, if all this were not a dream- Billy and Sue-so similar despite the wide divergence of their words, a wider divergence than the mind can well grasp, for how can one measure the distance between mutually incompatible things? Billy who was all of Bill Cory that was strong and resolute and proud; Sue, who incarnated his gentler qualities, the tenderness, the deep desire for peace. They were such poles apart-why, they were the poles! The positive and negative qualities that, together, made up all that was best in Bill Gory. Even their worlds were like two halves of a whole; one all that was strong and ruthless, the other the epitome of gentle, abstract idealism. And both were bad, as all extremes must be.

And if he could understand the purpose behind the fact that these two poles of human destiny had reached back in their own pasts to find him at the same moment-if he could understand why the two halves of his soul, split into positive and negative ent.i.ties, stood here clothed almost in his own flesh to torture him with indecision, perhaps- He could not choose between them, for there was no choice, but there was a deeper question here than the simple question of conduct. He groped for it blindly, wondering if the answer to everything might not lie in the answer to that question. For there was purpose here vaster than anything man has words for-something loomed behind it to shadowy heights that made his mind reel a little as he tried to understand.

He said inadequately to both his staring children: "But why . how did you. . . at this very moment out of all time-"

To Billy it was mere gibberish, but Sue must have understood the question in his mind, for after a moment, in a puzzled murmur, she said: "I-don't know, exactly. There is something here beyond the sim-pie fact of success. I. . . I feel it- I can sense something behind my own actions that. . - that frightens me. Something guiding and con-trolling my own mind- Oh, father, father, I'm afraid!"

Every protective instinct in him leaped ahead of reason in Bill's 'in-stant, "Don't be frightened, honey! I won't let anything happen to you!""Dr. Coryl" Young Billy's voice cracked a little in horror at what must have sounded to him like raving madness. Behind him, staring faces went tense with bewilderment. Above their rising murmurs Sue wailed, "Father!" in a frightened echo to Billy's, "Dr. Cory, are you ill, sir?"

"Oh, wait a minute, both of you!" said Bill wildly. And then in a stammer, to stop Billy's almost hysterical questions, "Your. . . your sister- Oh, Sue, honey, I hear you! I'll take care of you! Wait a minute!"

In the depths of the cube the boy's face seemed to freeze, the eyes that were Marta's going blank beneath the steel cap, Bill's very mouth moving stiffly with the stiffness of his lips.

"But you never had a daughter-"

"No, but I might have, if-I mean, if I'd married Sallie of course you'd never even- Oh, G.o.d!" Bill gave it up and pressed both hands over his eyes to shut out the sight of the boy's amazed incredulity, knowing he'd said too much, yet too numbed and confused now for diplomacy. The only clear idea in his head was that he must somehow be fair to both of them, the boy and the girl. Each must understand why he- "Is the doctor ill, Candidate Cory?" Dunn's voice was heavy from the cube.

Bill heard the boy's voice stammering: "No-that is, I don't-" And then, faltering, more softly: "Leader, was the great doctor ever- mad?"

"Good G.o.d, boy!"

"But-speak to him, Leader!"

Bill looked up haggardly as Dunn's voice rolled out with the sternness of a general addressing armies.

"Pull yourself together, sir! You never had a daughter! Don't you remember?"

Bill laughed wildly. "Remember? I've never had a son yet! I'm not married-not even engaged! How can I remember what hasn't hap-pened?"

"But you will marry Marta Mayhew! You did marry her! You founded the great line of Corys and gave the world your-"

"Father . . . father! What's wrong?" Sue's sweet wail was in his ears. He glanced toward her window momentarily, seeing the terror in the soft brown eyes that stared at him, but he could only murmur: "Hush, darling-wait, please!" before he faced the Leader and said with a strong effort at calmness, "None of all that has happened- yet."

"But it will-it must-it did!"

"Even if I never married Marta, never had a son?"

Dunn's dark face convulsed with a grimace of exasperated anger.

"But good Lord, man, look here!" He seized Billy's blue-uniformed shoulders with both hands, thrusting him forward. "You did have a son! This is his descendant, the living likeness of young Gory Junior! This world . . . I myself . . . all of us - . . we're the result of that marriage of yours! And you never had a daughter! Are you trying to tell us we don't exist? Is this a. . . a dream I'm showing you?" And he shook the boy's broad young shoulders between his hands. "You're looking at us, hearing us, talking to us!

Can't you see that you must have married Math Mayhew?"

"Father, I want you! Come back!" Sue's wail was insistent.

Bill groaned. "Wait a minute, Dunn." And then, turning, "Yes, honey, what is it?"

On her knees among the myrtle leaves Sue leaned forward among the sun-flecked shadows of her cool green glade, crying: "Father, you won't. . . you can't believe them? I heard.. . through your ears I heard them, and I can understand a little through your mind linked with mine. I can understand what you're thinking. . . but it can't be true! You're telling yourself that we're still on the Probability Plane - . . but that's just a theory! That's nothing but a speculation about the future! How could I be anything but real? Why, it's silly! Look at me! Listen to me! Here I am! Oh, don't let me go on thinking that maybe. . . maybe you're right, after all. But it was Sallie Carlisle you married, wasn't it, father? Please say it was!"

Bill gulped. "Wait, honey. Let me explain to them first." He knew he shouldn't have started the whole incredible argument. You can't convince a living human that he doesn't exist. They'd only think him mad.

Well- Sue might understand. Her training in metaphysics and telepathy might make it possible. ButBilly- He turned with a deep breath and a mental squaring of shoulders, determined to try, anyhow. For he must be fair. He began: "Dunn, did you ever hear of the Plane of Probability?"

At the man's incredulous stare he knew a dizzy moment of wonder whether he, too, lived in an illusion as vivid as theirs, and in that in-stant the foundations of time itself rocked beneath his feet. But he had no time now for speculation. Young Billy must understand, no matter how mad Dunn believed him, and Sue must know why he did what he must do-though he didn't understand himself, yet, what that would be.

His head was ringing with bewilderment.

"The . . . the Plane of Probability?" In Dunn's eyes upon his he saw a momentary conviction flare that, reality or not, and history be d.a.m.ned, this man was mad. And then, doubtfully, the Leader went on, "Hm-m-m - . . yes, somewhere I have heard- Oh, I remember. Some clap-trap jargon the old Telepathy House fakers used to use before we cleared them out of Science City. But what's that nonsense got to-"

"It's not nonsense." Bill closed his eyes in a sudden, almost intoler-able longing for peace, for time to think what he must do. But no, the thing must be settled now, without time for thinking. And perhaps that was the best way, after all. A man's brain would crack if he paused to think out this madness. Only he must say something to young Billy- And what could he say? How could he face either of these beloved children and, to their uncomprehending, pleading faces, refuse them life? If he could only break the connection that riveted them all into a sort of triple time balance- But he couldn't. He must make it clear to Billy- "It's not nonsense," he heard his own voice repeating wildly. "The future-you and your world-is a probability only. I'm a free agent. If I never marry Marta, never perfect the s.e.x-determination idea, the probable future shifts to . . . to another pattern. And that as bad as yours, or worse!" he finished to himself.

"Is he mad?" Billy's voice was a whisper in the screen.

The Leader said as if to himself, in an awed and stumbling voice, "I don't . . . I can't . . . the thing's preposterous! And yet he is un-married, the Great Work's still unfinished. Suppose he never- But we're real! We're flesh and blood, aren't we? He stamped a booted foot on the floor as if to test the foundations of his world. "We're de-scended in an unbroken line from this . . . this madman. Lord in heaven, are we all mad?"

"Father! Come back!" Sue's voice shrilled in Bill's ears. He turned desperately, glad of an excuse to escape the haunted stares from that other window even though he must face hers. She had risen to her feet among the myrtle leaves. The glade was cool and still about her in this lazy, sunlit world of her own future. She was crying desper-ately, "Don't listen, father! I can feel the confusion in your mind. I know what they're saying! But they aren't real, father-they can't be! You never had a son, don't you remember? All this you're saying is just. . . just talk, isn't it? That silly stuff about the Probability Plane -it's nothing but speculation! Oh, say it is, father! We've got such a lovely world, we love living so. . . I want to live, father! I am real! We've fought so hard, for so many centuries, for peace and happiness and our beautiful garden world. Don't let it snuff out into noth-ingness! But"-she laughed uncertainly-"how could you, when it's all around us, and has been for thousands of years? I. . . oh, father!" Her voice broke on a little quivering gulp that made Bill's heart quiver with it, and he ached intolerably with the rising of her tears. She was his to protect and cherish, forever. How could he- "Dr. Gory-do you hear me? Oh, please listen!" Young Billy's fa-miliar voice reached out to him from that other future. He glanced to-ward him once, and then put his hands to his ears and whirled from them both, the two voices mingling in an insane chaos of pleading.

Sue on her myrtle bank in a future immeasurably far ahead, child of a decadent world slipping easily down the slope of oblivion.

Billy's world might be as glorious as he believed, but the price was too high to pay for it. Bill remembered the set, unsmiling faces he had seen in the streets of that world. These were men his own work had robbed of the initiative that was their birthright. Happiness was their birthright, too, and thepower to make the decisions that de-termined their own futures.

No, not even for such achievements as theirs must mankind be robbed of the inalienable right to choose for himself. If it lay in Bill Gory's power to outlaw a system which destroyed men's freedom and honor and joy, even for such an end as mankind's immortal progress, he had no choice to make. The price was too high. COnfusedly he remembered something out of the dim past: "What shall it profit a man if he gain the whole world and lose his own soul. . . .

But-the alternative. Bill groaned. Happiness, peace, freedom, honor-yes, Sue's world had all that Billy's lacked. And to what end? Indolence and decadence and extinction for the great race that Billy's civilization would spread gloriously among the stars.

"But I'm thinking of choice," groaned Bill to himself. "And, I haven't got any choice! If I marry Sallie and don't finish my work- one future follows. If I marry Marta and do finish it, the other comes. And both are bad-but what can I do? Man or mankind; which has the stronger claim? Happiness and extinction-or unhappiness and splendid immortality; which is better?"

"Gory-Dr. Cory!" It was Dunn's voice, heavy enough to break through the daze of bewilderment that shrouded Bill's brain, lie turned. The Leader's iron-hard face under the steel helmet was set-tling into lines of fixed resolution. Bill saw that he had reached some decision, and knew a sudden, dazed admiration for the man. After all, he had not been chosen Leader for nothing.

"You're a fool to tell us all this, Gory. Mad, or a fool, or both. Don't you know what it means? Don't think we established this con-nection unprepared for trouble! The same force that carries the sight and sound of us from our age to yours can carry destruction, too! Nowhere in our past is there a record that William Gory was killed by a blast of atom-gun fire as he sat at his desk-but, by G.o.d, sir, if you can change that past, so can we!"

"It would mean wiping yourself out, you know," Bill reminded him as steadily as he could, searching the angry eyes of this man who must never have faced resolute opposition before, and wondering if the man had yet accepted a truth that must seem insanely impossible to him. He wanted overwhelmingly to laugh, and yet somewhere inside him a chilly conviction was growing that it might be possible for the children of his unborn son, in a future that would never exist, to blast him out of being. He said: "You and your whole world would vanish jf I died."

"But not unavenged!" The Leader said it savagely, and then hesi-tated. "But what am I saying? You've driven me almost as mad as you! Look, man, try to be sensible! Can you imagine yourself dissolv-ing into nothingness that never existed? Neither can II"

"But if you could kill me, then how could your world ever have been born?"

"To h.e.l.l with all that!" exploded Dunn. "I'm no metaphysician! I'm a fighting man! I'll take the chance!"

"Please, Dr. Gory-" Billy pressed forward against the very surface of the cube, as if he could thrust himself back into his own past and lay urgent hands upon this man so like him, staring white-faced and stubborn into the future. Perhaps it was more than the desire for peace that spoke in his shaken voice. If Bill Gory, looking into that young face so like his own, had felt affection and recognition for it, then must not the boy know a feeling akin to it as he saw himself in Gory's features? Perhaps it was that subtle, strange identification be-tween the two that made the boy's voice tremble a little as if with the first weakening of belief. When he spoke he seemed to be acknowl-edging the possibility of doubt, almost without realizing it. He said in that shaken, ardent voice: "Please, try to understand! It's not death we're afraid of. All of us would die now, willingly, if our deaths could further the common good. What we can't endure to face is the death of our civilization, this marvelous thing that makes mankind immortal. Think of that, Sir! This is the only right thing possible for you to do! Would we feel so strongly if we weren't sure? Can you condemn your own race to eternity on one small planet, when you could give them the universe to expand in and every good thing science can offer?"

"Father. . . father!" It was Sue again, frantic and far away.But before Bill could turn to her, Dunn's voice broke in heavily over both the others. "Wait-I've made up my mind!" Billy fell back a little, turning to his Leader with a blaze of sudden hope. Bill stared. "As I see it," went on Dunn, "the whole preposterous question hinges on the marriage you make. Naturally I can't concede even to myself that you could possibly marry anyone but the woman you did marry- but if you honestly feel that there's any question in your own mind about it, I'll settle it for you."

He turned to nod toward a corner of the room in which he stood that was outside Bill's range, and in a moment the blue-uniformed, staring crowd about him parted and a low, rakish barrel of blue-gleam-ing steel glided noiselessly forward toward that surface of the cube which was a window into the past-future that parted Bill and them-selves. Bill had never seen anything like it before, but he recognized its lethal quality. It crouched streamlined down upon its base as if for a lunge, and its mouth facing him was a dark doorway for death itself. Dunn bent behind it and laid his hand upon a half-visible lever in its base.

"Now," he said heavily. "William Gory, there seems to be a ques-tion in your mind as to whether we could reach you with our weap-ons. Let me a.s.sure you that the force-beam which connects us can carry more than sight and sound into your world! I hope I shan't have to demonstrate that. I hope you'll be sensible enough to turn to that televisor screen in the wall behind you and call Marta Mayhew."

"M-Marta?" Bill heard the quiver in his voice. "Why-"

"You will call her, and in our sight and hearing you are going to ask her to marry you. That much choice is yours, marriage or death. Do you hear me?"

Bill wanted insanely to laugh. Shotgun wedding from a mythical fu-ture-"You can't threaten me with that popgun forever," he said with a quaver of mirth he could not control. "How do you know I'll marry her once you're away?"

"You'll keep your word," said Dunn serenely. "Don't forget, Gory, we know you much better than you know yourself. We know your fu-ture far more completely than you saw it. We know how your charac-ter will develop with age. Yes, you're an honorable man. Once you've asked her to marry you, and heard her say yes-and she will-you won't try to back out. No, the promise given and received between you const.i.tutes a marriage as surely as if we'd seen the ceremony per-formed. You see, we trust your honor, William Gory."

"But-" Bill got no further than that, for explosively in his brain a sweet, high voice was sobbing: "Father, father, what are you doing? What's happened? Why don't you speak to me?"

In the tension Bill had nearly forgotten Sue, but the sound of that familiar voice tore at him with sudden, almost intolerable poignancy. Sue-the promise to protect her had risen to his lips involuntarily at the very mention of danger. It was answer to an urgency rooted race-deep, the instinct to protect the helpless and the loved. For a moment he forgot the gun trained on him from the other window; he forgot Billy and the world behind him. He was conscious only of his daugh-ter crying in terror for help-for help from him and for protection against him at once, in a dizzy confusion that made his head swim.

"Sue-" he began uncertainly.

"Gory, we're waiting!" Dunn's voice had an ominous undernote.

But there was a solution. He never knew just when he first became aware of it. A long while ago, perhaps, subconsciously, the promise of it had begun to take shape in his mind. He did not know when he first realized that-but he thought he knew whence it came. There was a sureness and a vastness about it that did not originate in himself. It was the Cosmic Mind indeed in which his own small soul was floun- dering, and out of that unthinkably limitless Plan, along with the problem came at last the solution. (There must be balance. . . the force that swings the worlds in their orbits can permit of no question without an answer-) There was no confusion here; there had never been. This was not chance. Purpose was behind it, and sudden confidence came flooding into him from outside. He turned with resolution so calm upon his face that Billy sighed and smiled, and Dunn's tense face relaxed.

"Thank G.o.d, sir," breathed Billy, "I knew you'd come to your senses. Believe me, sir, you won't besorry."

"Wait," said Bill to them both, and laid his hand on the b.u.t.ton be-neath his desk that rang a bell in his laboratory. "Wait and see."

In three worlds and times, three people very nearly identical in more than the flesh alone-perhaps three facets of the same person-ality, who can say?-stood silent and tense and waiting. It seemed like a very long time before the door opened and Miss Brown came into the room, hesitating on the threshold with her calm, pleasant face questioning.

"You want me, Dr. Gory?"

Bill did not answer for a moment. He was pouring his whole soul into this last long stare that said good-by to the young son he would never know. For understanding from some vast and nameless source was flooding his mind now, and he knew what was coming and why it would be so. He looked across the desk and gazed his last upon Sue's familiar face so like his own, the fruit of a love he would never share with pretty Sallie. And then, drawing a deep breath, he gulped and said distinctly: "Miss Brown, will you marry me?"

Dunn had given him the key-a promise given and received be-tween this woman and himself would be irrevocable, would swing the path of the future into a channel that led to no world that either Billy or Sue could know.

Bill got his first glimmer of hope for that future from the way the quiet woman in the doorway accepted his question. She did not stare or giggle or stammer. After one long, deep look into his eyes-he saw for the first time that hers were gray and cool behind the lenses-she answered calmly.

"Thank you, Dr. Gory. I shall be very happy to marry you."

And then-it came. In the very core of his brain, heartbreak and despair exploded in a long, wailing scream of faith betrayed as pretty Sue, his beloved, his darling, winked out into the oblivion from which she would never now emerge. The lazy green Eden was gone forever; the sweet fair girl on her knees among the myrtle leaves had never been-would never be.

Upon that other window surface, in one last flash of unbearable clearness, young Billy's incredulous features stared at him. Behind that beloved, betrayed face he saw the face of the Leader twisting with fury. In the last flashing instant while the vanishing, never-to-exist future still lingered in the cube, Bill saw an explosion of white-hot violence glare blindingly from the gun mouth, a heat and violence that seared the very brain. Would it have reached him-could it have harmed him? He never knew, for it lasted scarcely a heartbeat before eternity closed over the vanishing world in a soundless, fathomless, all-swallowing tide.

'Where that world had stretched so vividly a moment ago, now Marta's violet gaze looked out into the room through crystal. Across the desk Sallie's lovely, careless smile glowed changelessly. They had been gateways to the future-but the gates were closed. There would never be such futures now; there never had been. In the Cosmic Mind, the great Plan of Things, two half-formed ideas went out like blown candle flames.

And Bill turned to the gray-eyed woman in the doorway with a long, deep, shaken sigh. In his own mind as he faced her, thoughts too vast for formulation moved cloudily.

"I know now something no man was ever sure of before-our one-ness with the Plan. There are many, many futures. I couldn't face the knowledge of another, but I think-yes, I believe, ours will be the best.

She won't let me neglect the work we're doing, but neither will she force me to give it to the world unperfected. Maybe, between us, we can work out that kink that robs the embryo of determination, and then-who knows?

"Who knows why all this had to happen? There was Purpose be-hind it-all of it-but I'll never understand just why. I only know that the futures are infinite-and that I haven't lost Billy or Sue. I couldn't have done what I did without being sure of that. I couldn't lose them, because they're me-the best of me, going on forever. Perhaps I'll never die, really-not the real me-until these incarnations ofthe best that's in me, whatever form and face and name they wear, work out mankind's ultimate destiny in some future I'll never see. There was reason behind all this. Maybe, after all, I'll understand-some day."

He said nothing aloud, but he held out his hand to the woman in the door and smiled down confidently into her cool, gray eyes.