The lodge would have been in darkness when he arrived had it not been for the uneasily shifting brilliance of the aurora in the north, and the manic tracer-fire of meteors carving the night sky into diamond-shaped fragments. Breton got out of the car and walked quickly towards the lodge, pressing one hand on the outside of his jacket pocket to prevent the pistol from jarring against his hip. In the variable, unnatural light the solid lines of the fishing lodge seemed to shrink, quiver and expand in a kind of plasmatic glee. Once more Breton felt cold and desperately tired. He opened the front door and went into the sentient darkness, some instinct making him take the pistol out of his pocket. At the head of the basement stairs he hesitated before turning on the light. The blinking, then steadying, glow of the fluorescents revealed John Breton lying on his side in the center of the floor. His stained and dusty clothing gave him the appearance of a dead creature, but his eyes were intelligent, watchful. "I tried to get away," he said, almost casually, as Jack went down the stairs. "Nearly cut my hands off." He moved as if to try to exhibit his wrists, then his eyes took in the pistol in Jack's hand. "Already?" His voice was sad rather than afraid. Jack realized he had been half-hiding the weapon behind his body. Reluctantly, he brought it into full view. "Are you going to stand up?" "There hardly seems much point." John seemed aware that he had some obscure psychological advantage. "What would it achieve?" "All right." Jack released the safety catch on the pistol and aimed it. There was nothing to be gained by wasting time. Nothing in the world. "Ah, no." John's voice was beginning to quaver. "You're really going to do it, aren't you?" "I have to. I'm sorry." "I'm sorry, too -- for us all." "Save the piety for yourself." Jack tightened his finger on the trigger, but it seemed to have acquired the stiffness of a hydraulic ram, and the seconds dragged by. John lay still for a moment, then his resolve broke and he began to squirm frantically, trying to put distance between himself and the gun muzzle. His feet scrabbled on the concrete as he worked to back away. Jack braced his gun arm with his left hand, and went after him doggedly. At last the trigger began its stealthy, pre-orgasmic slide. Suddenly, cool air gusted past Jack Breton. He turned, almost firing the pistol in panic. A ghostly, transparent object hung in the air a few feet away. Breton's face contorted with shock as he identified the familiar, terrible, bilobular shape. A human brain! As he watched, a corded vertical column materialized beneath the insubstantial brain, followed by cloudly, branching networks of finer lines, until -- within the space of a second -- it resembled a three-dimensional plastic model of the human nervous system. There was a further, stronger, gust of cool air. And Jack Breton found himself staring, paralyzed, into the face of another man. I too must have looked like that, Jack Breton thought, in the first tortured instant. I must have looked like that -- once -- when I kept that rendezvous by the three trees . . . a naked brain, materializing there in the darkness, awful, pulsating, loathesome. With the spreading nervous networks reaching downwards, like a racing fungus, until they were clothed by my own flesh. It was one aspect of chronomotion he had never considered -- the arrival and its . . . The detailed, convergent thought was blotted out by a sudden, jolting awareness of its significance. "Put the gun away, Jack." The stranger spoke in a lifeless monotone which nonetheless conveyed a sense of crushing urgency. He moved closer to Jack Breton, and the overhead tube bathed his face in cold light. Breton's first impression was that Nature had made a hideous mistake in fashioning this face -- it seemed to have only one eye, and two mouths! As he brought it into visual and intellectual focus, he saw that the face had indeed only one eye. The missing orb had been completely excised, allowing the whole region of the socket to collapse inwards, and no attempt had been made to disguise or cover the loss. The upper and lower lids met each other in a perfect, sardonic little smile, startlingly similar to the one which twisted the stranger's lips. Breton received an impression of graying hair that failed to cover patches of diseased scalp, of heavily lined skin, of shabby strangely-styled clothes -- but all his attention was riveted on that ghastly second mouth. "Who . . .?" He forced the words out. "Who are you?" The answer came not from the stranger, but from the floor. "Don't you recognize him, Jack?" John Breton spoke with a kind of detached reproach. "That's yourself." "No!" Jack Breton stepped back, instinctively raising the pistol. "It isn't true." "But he is." John sounded revengeful. "This is the one aspect of this whole time travel business in which I've got more experience than you, Jack. You never gave me credit for recognizing and accepting you so quickly that first night . . ." "Don't argue!" The stranger interrupted tiredly but authoritatively, like a dying emperor. "I hadn't realized the two of you would be so like children -- and there's so little time." John Breton struggled to his feet. "Are you going to untie me?" "There isn't time," the stranger said, shaking his head. "I will use no violence, and will do nothing which might precipitate violence. I can use only . . . words." "I asked who you are," Jack Breton said. "You know who I am." The stranger sounded even more tired, as though his strength was failing. "When you were planning to cross into this time-stream you labeled yourself Breton A, and John here as Breton B. I have reason to dislike those unemotional tags -- so I'll accept the name of Breton Senior. It is much more appropriate." "I could put a bullet through you," Breton pointed out, almost irrelevantly, in an attempt to subdue the dismay he could feel building up inside him. "Why bother? You've made one trip back through time yourself, and have a good idea of what it does to the nervous system. You must know I can sustain this strain only for a very short period, and then I'll be sucked back to fill the temporal vacuum I've created in my own time." Breton nodded, remembering the way he had lain pole-axed in the grass after he had shot Spiedel. And that jump had lasted only a few seconds. He tried to visualize what Breton Senior would go through on his return, but his mind was already a whirling storm of half-formulated questions. . . . "You were able to make that jump because, combined with your unusual cerebral structure, you had an overpowering need to go back and correct a mistake. But your obsession led you into a vastly greater mistake. A mistake which has two entirely different aspects -- one of them personal, one of them universal." The older man's voice wavered slightly. He walked to the cluttered workbench and leaned against it. The stillness of his movements reminded Jack Breton of how difficult it had been to walk with the network of wires taped to his skin. "The personal mistake," Breton Senior continued, "was in not learning to live with the tragedy of Kate's death, and living with it includes accepting your share of the responsibility. Tragedies happen to many people, but the measure of their worth in human beings lies in their ability to surmount tragedy and find new meaning for their lives. "Does this sound like Reader's Digest stuff to you?" Jack Breton nodded. "I thought it might, but even you -- although you can't admit it -- have begun to realize the truth of what I've been saying. Where is the happiness you thought the Time B world held for you, Jack? Has it all worked out the way you expected?" Breton hesitated only momentarily, glancing across at John Breton. "It's working out. I have a problem with Kate, but that's a personal matter "Wrong!" Breton Senior's single eye gleamed like a beacon. "There's another reason you must return to your own probability world. If you don't, it means -- quite simply -- that you will have destroyed two universes!" The words had a strangely familiar ring to Jack Breton, as though he had heard them long ago, in a forgotten dream. His first instinct was to scream a denial, but some part of his mind had known for a long time . . . that the sky was his enemy. He felt his knees begin to swim. "Go on," he said faintly. "On what level do you want it?" "The most basic." "All right. As you'll remember from your intensive study of electrical phenomena, you decided that the basic problem in building a chronomotive device was the abrogation of Kirchoff's laws. You had a special interest in the second law and the fact that the algebraic sum of the electromotive forces in any closed circuit or mesh is equal to the algebraic sum of the products of the resistance of each portion of -- " "You'll have to make it more basic," Jack Breton interrupted. "I can't think." "Very well -- my time's running out, anyway. We'll move on to the law of conservation of energy and mass. The universe is an absolutely closed system, and has to obey the principal that the sum of its mass and energy must remain constant. Until you left the Time A universe it contained all the mass and energy that it had ever possessed or ever would possess." Breton Senior had begun to speak more quickly. "But you, Jack, are a creature of mass and energy, and in leaving the Time A universe you created a loss where no loss could possibly be sustained. And in entering the Time B universe you created a gain, an overload on the space-time fabric. Imbalances like that can be maintained only for brief periods . . ." "So that's it," John Breton said softly, coming into the conversation for the first time. "That's what's been going on -- the changes in the gravitic constant, the meteors, all the rest of it." He stared at Jack in startled speculation. "It did start that night you showed up. I remember it now. I even saw a couple of meteors when Gordon and Miriam were driving off. And that was the night Carl called up and said -- " "My time here is almost finished," Breton Senior cut in. He had slumped sideways on the bench and his voice had shrunk to an agonized whisper. "Jack, the longer you remain outside your own universe, the more certainly you will set up the growing imbalances which will destroy both time-streams. You must return -- now." "I still don't understand this." Jack Breton took a deep breath and tried forcing his brain into action. "You say that by remaining here I'll destroy the universe, yet you, apparently, have come back to this point in time -- from the future you say doesn't exist." "How big of a jump do you think I made?" "I don't know." Jack Breton began to feel afraid. "Twenty years? Thirty years?" Breton Senior pressed. "Something like that." "It was just over four years. "But . . ." Jack was aghast, and he noticed the shock register on John's face too. "I'm four years older than you are." Breton Senior made an obvious effort to rally his strength. "But I see that you still haven't grasped the situation fully. It's my fault for not making it clearer, but I assumed you would understand. . . . "Don't you see, Jack? I am what you will become if you murder your Time B self and live on in this time-stream with Kate. I went through with it, just as you were about to do when I got here, and I got away with it. "Got away with it!" Breton Senior laughed, in a way that Jack Breton had never heard anyone Laugh before, then he went on speaking -- but not to either of the men present -- his broken phases sketching in the lineaments of the face of Armageddon. As the bonds of gravity were slackened, the planets stole away from their parent sun, seeking new orbits commensurate with the altered balance of gravitic and radial forces. But they did not move quickly enough, for the Sun came after them like a demented mother intent on the slaughter of her own children. Bloated, swelling with the nuclear pus of her own dissolution, she bombarded her offspring with unimaginable quantities of lethal radiation. Breton Senior existed four years in a world which had become an arena for two different forms of death, each struggling for the maximum share of humanity's carcass. The ancient decimators of famine and plague warred with new competitors -- epidemic cancer and epidemic non-viable mutation. When Kate succumbed to a nameless disease, he discovered within himself something which had been absent since his first trip back through time -- the chronomotive potential, which in others was known as remorse. He began to build a new chronomotor and, even though hampered by the loss of a diseased eye, finished it in a matter of weeks. His intention was to persuade Breton A to go back into his own time-stream, thus restoring universal balance before it was too late. If he was successful, the B time-stream leading to the death of the universe would still continue on its accelerating downwards course -- nothing could be done about that -- but it would also produce an offshoot stream. This would be a modified Time B probability world in which Kate and John Breton could live out their lives in peace. The rewards, as far as Breton Senior was concerned, would be philosophical rather than practical -- for the cold equations of chronomotive physics dictated that if he tried to enjoy that world his presence there would destroy it. But, having seen what he had seen, he was prepared to settle for the knowledge that the other world existed, somewhere, somewhen. At first, when arranging the jump, he planned to take a rifle and make sure that Jack Breton returned to his own universe -- just as, in that remote earlier life, he had ejected Spiedel from the land of the living. But that would have been the easy way, and he had done with killing. If he could not influence Jack Breton by reason alone, then he would die with the awful burden of knowing that he had taken every other living creature in the universe with him. . . .