“Might as well,” Camacho said. “Hoyle’s suggestions turned out to fit in with certain results of nuclear research. The whole theory was developed in detail by Bishop. He got one particularly interesting result. The existence of the matter-creation field is equivalent to the unity of space. By modifying some parameters of it, which can be done with nuclear binding energies, you can in effect open a way directly from anywhere to anywhere. You establish a plane of contiguity, a jumpgate and walk on through. There is no limit to the distance you can go.

  “Except for the energy differential, of course. Suppose, for example, you wanted to go from Earth to Mars. Now Earth travels around the sun at almost thirty kilometers per second, Mars·at twenty-four. If you simply opened a gate between them, you’d have the problem of stepping out onto a landscape traveling past you at six K.P.S. without breaking your neck. Not to mention differences in rotation speed or in planetary and solar gravitational potential.

  “You could wait until the exact moment came when the motions of the two planets were in such directions that they cancelled out all these various energy differences. Then there’d be no problem. But if you don’t want to be restricted to that very narrow time slot, you can take the long way around. Maybe, at this instant, a planet of Tau Ceti is just a wee bit different in energy from Earth; and a planet of Epsilon Indi a wee bit more; and so on and so on, until finally you reach Mars.

  “In general, then, to get from one world to another, you have to pick a route. This route is never the same twice running. And naturally it has to go through places where men can walk. The surface of Jupiter wouldn’t do! So to explore space via the jumpgate is nowhere as simple as it looks. First you have to collect data on way stations, by instruments and manned expeditions. Next you have to put those figures through a computer, continuously. Often you have to wait before making a certain trip, because there simply aren’t any useable intermediate points at the moment. But we are discovering more and more of them all the time. It gets easier as we go along.”

  Camacho paused before finishing, deliberately: “At least, within this galaxy it does.”

  “Very good!” Vahdati applauded. “I do not know whether to admire most your grasp of the subject or your sheer laryngeal capacity.”

  “Thanks,” Camacho said. “They’re both part of a politician’s stock in trade.” Noting a slightly surprised look, he added in some irritation: “Yes, also a knowledge of basic facts. My job is to deal with people. That means I’d damn well better understand what people are up to.”

  They reached their destination. A ramp curved toward the Martian surface. At its foot stood an intervisi and a locker.

  Vahdati extracted a couple of airsuits. “Standard precaution,” he said. “If perchance something goes wrong, these will keep us alive for the time necessary to escape. Going onto a completely new world, or one where no booth has been constructed yet, we would use regular spacesuits. But those are far more cumbersome and must be designed to individual specifications.”

  Camacho struggled into his outfit with much help from the other. The result was romantic—boots, gauntlets, and powerpack belt above a padded coverall with interwoven thermostatic coils. The helmet bore self-darkening goggles; a chin pad could be slipped over nose and mouth to become a mask supplying several minute’s worth of oxygen. With a shyness that surprised himself, Camacho handed over the camera he had doffed with his civilian clothes. “Uh, would you mind taking my picture? I promise you it’s not for campaign purposes. Only for my children.”

  Vahdati chuckled and obliged. “We will take this along and get you against exotic backgrounds, too,” he promised. Turning to the intervisi, he switched in an Oriental face. “Central Control from Gate Four,” he said. “Hullo, Nagamura. We are ready. Have you our program?”

  “Yes, sir. First a look at Orion, then you proceed to Yrnay. We have computed you will require five intermediate stops. Here is your program.” The ’visi pinged and extruded a printout which Vahdati took. “You start in four minutes.”

  “Check.” The Iranian reached back into the locker and got a pair of laserifles. “We will have no use whatsoever for these silly things,” he apologized, “but since we will be on planets known to have large animals, regulations insist.”

  “Send me some testimony when I get back, and I’ll see if the rules can’t be changed,” Camacho offered. “Meanwhile— Lord, don’t we look dashing?”

  “That is the trouble,” Vahdati said with unexpected bitterness. “Headlong dashes to what could be death…Pardon me. This way, please.”

  Continuing upramp, Camacho wondered what had been meant. Ian? Probably. Yet this fellow sure wanted a gate on Earth—

  They entered the booth.

  It jutted from the surface like a small monolith. Of reinforced vitrilene, it was practically invisible, so that you seemed to stand houseless in the middle of a gaunt and terrible land. Stony, sandy, even less vegetated than Mare Erythraeum, Lacus Solis reached to a horizon of weathered crags. Overhead arched the night sky of Mars, heartlessly brilliant constellations, Jupiter and Saturn as lamps, the swift discs of two nearby relay satellites. The main station was a hump of darkness with goblin eyes. In the opposite direction, a rocketship kept in case of emergency made a lean tower.

  At hand was the hearthfire glow of an instrument console. And the gate: a framed metal slab occupying the center of the booth. Stillness pressed inward until Camacho could hear the blood knock in his ears. He felt, too, a quiver at the base of his throat and a trickle of sweat from his armpits, and he drank the scent of his own body.

  Vahdati’s parched tone was a relief: “I am sure you know how this works, but I am required by law to brief you. We will not be making a simple point-to-point transition, as between here and Port Nikolai. Instead several different planes must be made contiguous, one after the next. Each booth where we are going has its own gate, is in fact very much like the one we are now in. However, none of them possess an ordinary exit. They are shelters against lethal environments.”

  He busied himself as he talked, sliding a curved, transparent shield across the door frame and locking it in position. “Of course,” he said, “our first exit will be directly onto interstellar space. We don’t want to lose air. This is merely an, ah, appetizer.” He finished. A bell sounded. “Now! Come around in front—so.”

  Meter needles stirred and steadied. Vahdati waved open the door. Camacho gasped.

  -5-

  The frame enclosed blackness, but in that dark swirled vast inchoate thunderclouds. They shone in all hues of the rainbow and in the richer, purer colors of ultraviolet fluorescence—fiery, golden, verdant, cerulean. Had his goggles not shifted optical density at once he might have been blinded, for he could not look away.

  Slowly, through his awe, he made out separate features. Those luminous curdles, they must be suns in the process of getting born…if he could step through the gate, how many light-years from home would he be?…this was the great nebula in Orion…was it only his bloodbeat he heard, or the querning of the galaxy?

  Vahdati plucked the camera from his fingers and took a few shots. “If any watchers are out yonder,” the Iranian remarked “they see an open door hanging in space, with Mars and ourselves inside.” His words hardly registered. He began to shut the panel.

  “Don’t,” Camacho begged.

  “I must,” Vahdati said. “We are only allowed sixty seconds without special radiation protection.”

  Again bare steel confronted Camacho. He lifted his goggles and dabbed at his eyes.

  “I know,” Vahdati said softly. He busied himself removing the airshield.

  With considerate briskness: “Now we travel. In one minute I am to open the gate on Way Station 348. We have run out of names, but it is a satellite of the giant planet Osiris, 61 Cygni C.” He slung rifle and camera on his shoulders. “The two gates, this one and the one there, will be physically aligned, snugged against each other with their doors, swinging in opposite directions, as long as connection is maintained. Now, going through involves a slight shock. Hold my arms thus and so, I will brace you.”

  Camacho cast a last glance around Mars. Power hummed again and died. Vahdati opened the door. “Through!”

  They crossed the double threshold.

  The change in kinetic and potential energy, and the yank of gravity somewhat higher than Earth’s, made Camacho stumble. He would have fallen, but for the Iranian’s support. After a moment, he was able to stand and stare.

  At his back, now, was framed Lacus Solis. Its harshness looked homelike. Around him reached a plateau sheathed in ice, mountains climbing toward a dusky purple sky and two wan red suns. The light was blood color. Behind a veil of scudding snow loomed the primary planet, a swollen orange shield banded in umber and green, speckled with storms that could have swallowed Earth whole. Wind-shriek struck through the booth, and a wave of cold came from the unseen walls to lave his face.

  Vahdati glanced at his watch and at the printout he carried. “The program allows us two hundred seconds here,” he said. “Get your pictures fast.”

  Numbly, Camacho obeyed. He hoped they would turn out. Vahdati tugged his arm, leading him around to the front of the joined gates. Looking through them from this side, Camacho did not see Mars, only the nameless world on which he stood, as if the frames were empty—which, in a sense, they were. Vahdati closed the doors and touched a switch. One gate vanished; frame, panel, controls, and all, it simply wasn’t in this booth any longer. Vahdati made adjustments and operated the remaining unit.

  “Through!”

  The impact of energy transfer was a little greater, the weight that followed a little less.

  Now it was the view of Osiris which hung behind the men. Outside, mist swirled blue-gray, condensed on the vitrilene and poured down so that Camacho could barely glimpse trees beyond. They had no leaves, but ruddy fringes along the boughs were always in motion though there seemed to be no breeze. A sound akin to flutes trilled faintly in Camacho’s hearing.

  “Where are we?” he whispered.

  “I don’t know,” Vahdati said. “Who can remember each of several thousand stops? But the gate settings I made are such that I know we have gone about nine hundred light-years from Sol in the direction of Cassiopeia.”

  “What’s…the local…condition?”

  “That is posted in every booth. Here, see. Orbital and planetographical data…atmosphere, well, has oxygen, but too much carbon dioxide for us. We are to stay three minutes.”

  The next planet had another ember for a sun. Red dwarf stars are by far the commonest type. Curious metallic growths swayed on the strand of a night-black sea, under a greenish heaven. This globe had been christened; Vahdati knew something about it and spent the half hour’s wait talking. For that matter, Camacho had read news reports. A biology so alien to Earth’s or Mars’s was irresistible research bait. Expeditions had taken spaceships through the big gate at Port Nikolai and made maps from orbit. In a hundred years, ground-based surveys might fill in a fair number of details. It would take longer to answer the scientific questions.

  The fourth world was closer to home, in fact only thirty-odd light-years away, the innermost planet of Groombridge 1830. As such, however, it moved usefully fast in orbit. The landscape was airless, lifeless and beautiful.

  Camacho saw little at the fifth stop. The sun was type F5, a savage ultraviolet emitter, and the walls must be screened. Through a televiewer, he spied leaping things that glittered in the dazzle.

  Then they reached Yrnay. Here no booth existed: rather, an elaborate house. They must cycle through decontamination; it was not yet absolutely certain that no micro-organism from one planet could do harm on the other. But they walked out into soft, scented air, among green-fronded plants and were welcomed by the personnel of the permanent scientific base.

  Camacho was more interested in what followed—when, as a VIP, he got a full day’s visit to the nearest autochthonous community. That was heartbreakingly short, of course. He carried away little but a kaleidoscope of the utterly strange and utterly lovely and a resolve to learn everything he could about this place. Which wouldn’t be much, really, not when men had just begun talking to a civilization as old as their own, or older, sundered by three or four billion years of separate evolution. Come back in a millennium, he was told, and maybe we’ll understand.

  But when he had to return to Mars, and Vahdati asked quietly, “Do you see now why we are anxious to expand our program?” Camacho could do no more than nod.

  -6-

  Dining in the messhall, the senator spent time at affability toward the staff which he would rather have devoted to studying the reports which had been supplied him. They weren’t easy reading. Not only were they in pure technicalese, but no effort had yet been made to put the facts down in logical sequence. He wondered if that was deliberate; the news of his coming had arrived long before he did.

  As a result, he didn’t finish till late on the second day. Then he called Lawson. “Could we talk privately tomorrow?” he asked. “Maybe with Dr. Vahdati present, but no others. You know how impossible it is to argue efficiently in a committee.

  “Come right now if you will,” the director said rather sourly. “I am free. I won’t be tomorrow. We’re busy setting up a new experiment to try and find what caused the accident.”

  Camacho hesitated. I suspect they’d sooner I don’t get a chance to organize my thoughts, he reflected. Okay, I’ll show ’em. “I’ll be right over to your office. Thanks.”

  The room was reminiscent of Nahabedian’s—also in a turret with a full view of the landscape. Off in the distance, under gnawed rockspires, machinery and instruments surrounded the splinters of what had been a gatebooth—the one that Ian went through. The sun was on the horizon, small and cold, and shadows reached across the desert like fingers.

  Camacho and Vahdati took chairs. Lawson sat behind his desk, drumming nervously on its top. The senator longed for a cigar but had to settle for the pack of Gaulois Bleu which was all he had been able to get in Port Nikolai. Vahdati accepted his offer of one; Lawson refused.

  “Well, sir, have you reached any conclusions?” the Iranian asked after a silence. He smiled lopsidedly. “If so, you are a better man than I.”

  Camacho drew in a puff of acrid smoke and trickled it out his nostrils before replying. “I’m not sure. Frankly, I never expected any nice, clean-cut answer. Life doesn’t work that way. I’ll probably just collect a mess of impressions.”

  “And on that basis you will legislate?” Lawson exploded.

  Camacho simply watched him till he swallowed his anger and mumbled, “Sorry. No offense. But I don’t understand how you can justify regulating scientific affairs on unscientific principles.”

  “Science isn’t a god, you know,” Camacho said mildly, “not even a concrete object. It’s something people do. So it’s subject to the same considerations of morality, the public weal, I might go so far as to say good taste, as any other human activity. And applying those principles has to be done by ear. No other sane way. Every time that government fell into the hands of dedicated intellectuals, the result was disaster. Look at the French or Russian Revolutions.”

  “All right.” Lawson hunched forward. “But doesn’t the general welfare call for a continued expansion of scientific knowledge and the full use of what knowledge we have already gained?”

  “Up to a point. It might, for instance, be an interesting experiment to see if we could blow up Earth. The results might tell us a great deal. However, I’d have to veto any such proposal.”

  “Please don’t erect straw men. Which that old stellar-interior argument is!”

  “Not exactly.” Camacho rolled his cigarette between his fingers and scowled at the glowing end. “We’re a long ways from having detected every faint star in this neighborhood, let alone throughout the Cosmos. Even for those stars we can see, we don’t know within many million kilometers where they lie, until we’ve actually visited them. So a gate could be opened on the center of a star. No matter how small a star, that’d be the end of the planet where the gate stood. We can’t risk Earth! We can’t risk Luna either. Think what tideless oceans would become. Mars is expendable.”

  “But nobody wants to take that chance! A gate on Earth or Luna would lead only to Mars via suitable way stations. From here, travelers would make a transfer. We could time things if you insist, so that no Martian gate is open when the terrestrial one is.”

  “We could go further than that to compromise with you,” Vahdati added. “One or more gates, actually on Earth, would be a tremendous convenience. But they are not absolutely necessary. Why will you not let any gate anywhere in the universe, be opened on Earth?”

  “The hazard’s still too great” Camacho answered. “How about biological contamination? We haven’t yet met an extra-Solar disease we couldn’t lick but there’s always a first time and it might have a long incubation. At present, the spaceship voyage amounts to a quarantine period.” He shrugged. “I could go on naming possible horrors, but you say you’ve read my speeches. The point right now is, something happened to Ian Birkie which you can’t explain. Could it be some hitherto unsuspected phenomenon involving the gates themselves?”

  “No,” said Lawson flatly. “Haven’t we enough experience to be sure of that much? It was something unique, occurring near the edge of the universe.”

  “Edge…does that phrase mean anything? I thought every galaxy was at the center of the universe, as far as itself was concerned.”

  Lawson sighed theatrically. “You are good at explaining,” he said to Vahdati. “Suppose you try.”

  “Well—” the Iranian stubbed out his cigarette. “Probably you already know this, Senator. If so, forgive me. But the complementarity principle is difficult to see. In effect what it says is that all our descriptions of reality are necessarily limited and incomplete. Two different pictures may be equally valid, each emphasizing some particular aspect. The obvious case is in sub-nuclear physics. Does matter consist of particles or of waves? That question is empty. The proper question is: In any given situation, does the wave or the particle description work best?”