Protector

by Larry Niven

  He spotted Brennan’s torch.

  Brennan was working in vacuum, building…something. His redesigned pressure suit seemed both alien and anachronistic, and the chest design was a detail from Dali: a Madonna and Child, very beautiful. A torn loaf of bread floated within the window in the Child’s torso, and he looked down at it with an adult, thoughtful gaze.

  “Don’t come too close,” Brennan said into his suit mike. “I had plenty of time to fiddle with this ball of rock while I was shaping Kobold. There are deposits of pure elements under all this landscaping.”

  “What are you making?”

  “Something that should collapse a polarized gravity generator at a distance. If generated gravity is what they’re using to hold their ships in tandem, they’ll have to polarize it to make it work over those distances. We know they know how to do it. They’ll put the generator on the trailing ship, because that’s the ship that’s producing enough excess power to maintain the field.”

  “Suppose they’re using something else?”

  “So I waste a month. But I won’t believe they’re using cables. In deceleration mode even a Pak cable won’t stand up to the exhaust from the trailing ship. I might believe they loaded everything on the trailing ship and used the lead ship purely as a stripped Bussard ramjet—a compressor. But they’d lose power and maneuverability.

  “I’ve been trying to design a Pak scout ship myself. It isn’t easy, because I don’t know what they’ve got. The worst thing I can think of from our viewpoint is two independent ships with heavy, versatile ram field generators. That way if you lost a couple of lead ships in a battle, you could link the trailing ships, and vice versa.”

  “Yah.”

  “But I don’t believe it. The more widgetry they put into each ship, the fewer ships they wind up with. I think they’d compromise. The lead ship is a Bussard ramjet, built to fight, but not too different from ours. It’s the trailing ship that’s versatile, with the oversized adjustable ram field generator. You could link two trailing ships, but not two lead ships. The lead ships are more vulnerable anyway. You saw that.”

  “Then these scouts are tougher than what I fought.”

  “And there are three of them.”

  “Three.”

  “They’re coming in a cone, through—you remember that map of the space around Sol? There’s a region that’s almost all red dwarfs, and they’re coming through that. I think the idea is to map an escape route for the fleet, in case something goes wrong at Sol. Otherwise they’ll see to it that Sol is clean, then go on to other yellow dwarf stars. At the moment they’re all about a light year from Sol and about eight light-months apart.”

  Roy looked up. Where within the battlefield—? He found Sol easily, but he couldn’t remember the direction of the first scout. He shivered in his suit, though it was far more comfortable than it had ever been. Brennan had been tinkering with it.

  “There could be more.”

  “I doubt it,” said Brennan. “I didn’t find any more beryllium traces at any frequency shift.”

  “Suppose they came in ones instead of twos. They’d show as ordinary Bussard ships.”

  “I don’t believe it. Look, they need to be able to see each other. If a scout disappears, the others want to know it.”

  “All right. Now we’ve got to keep them away from Sol. How about using ourselves as a decoy?”

  “Right.”

  That absent-minded monosyllable was disconcerting. It happened every so often, this implication that Brennan had already thought it through, in every detail, long ago. When he didn’t say any more, Roy asked, “Anything I can do to help?”

  “No. I’ve got to finish this. Improve your mind. Brush up on local astronomy; it’s our battle map. Look up Home. We’re not going to Wunderland now. We’re going to Home, if we get the choice.”

  “How come?”

  “Let’s say I’m planning to make a right angle turn in deep space. Home’s the easiest target after that. They’ve also got a good industrial civilization.”

  HOME: Epsilon Indi 2, second of five planets in a system which also includes 200 asteroids randomly distributed in charted orbits. Gravity: 1.08. Diameter: 8800 miles. Rotation: 23 hours 10 minutes. Year: 181 days. Atmosphere: 23% oxygen, 76% nitrogen, 1% nontoxic trace gasses. Sea level pressure: 11 pounds/square inch.

  One moon, diameter: 1200 miles, gravity: 0.2, surface composition: roughly lunar.

  Discovery reported 2094, via ramrobot exploration probe. Settled 2189, by a combination of slowboats and ramrobots…

  Settling Home had been made easier by two new techniques. The slowboats had carried sixty colonists each, in stasis. Sixty colonists would have filled three or four slowboats a century earlier. And, though no living thing could survive travel in a ramrobot, it had proved possible to ship fuel to the slowboats via ramrobot. An older technique was used extensively: colony supplies were shipped via ramrobot to orbit about Home, saving room aboard the slowboats. Rams that failed on the way would fail in time for replacements to be sent.

  The original colonists had planned to call their new world Flatland. Perhaps it amused them to think of themselves and their descendants as flatlanders. Once on Home they had changed their minds: a belated attack of patriotism.

  Population: 3,200,000. Colonized area: 6,000,000 square miles. Principal cities…Roy spent some time memorizing the maps. Cities and towns had tended to form in the forks of rivers. The farming communities were all near the sea. Home had sea life but little land life, and farming of any kind required a complete ecology; but sea life was used extensively for fertilizer.

  There were extensive mining industries, all confined to Home itself.

  Communication with Earth formed a principal industry, which tended to produce other industries at a steady rate.

  Three million…A population of three million at this date meant a heavy birthrate, even if initially augmented by bottle-grown babies and later by more colony ships. Roy hadn’t thought of that aspect of moving to a colony world. There was a pride in being the father of many children…a pride that would have less meaning on Home, where you didn’t have to prove genius or invent the wheel or something just to get the license. Still…he would have children on two worlds.

  Still, Home would probably change for the worse when Brennan put it on a war footing. War was never fun, and—Roy ought to know—this kind of interstellar war was going to be long and slow. What kind of mind did it take to plan a hundred and seventy-three years in advance?

  The thing Brennan was building was slightly taller than he was, heavy and cylindrical. He had moved it near one of the great doors beneath which the components of Protector waited.

  “I want to be damn sure I can get adequate polarization of the field,” he told Roy. “Otherwise the whole of Protector could wind up falling into it.”

  “Like Kobold, huh? Can you do it?”

  “I think so. The Pak did it…we assume. If I can’t do it I’ll have to assume they’re holding their ships in tandem some other way.”

  “Where’s it going to ride?”

  “I’ll string it behind the weapons pod. And your cargo ship behind the lifesystem. We’ll look somewhat strung out. It won’t surprise the Pak any that I’ve fiddled with the design of the ship. They would, given the tools and raw materials.”

  “What makes you think they don’t have them?”

  “I don’t think that,” said Brennan. “I keep wondering what they’ll build for me once they know what I’ve got.”

  One day he was back in the observatory. “All finished,” he said briskly. “I can get the polarized gravity field I need. Which means a Pak could get it, which means they’re probably using it.”

  “Then we’re ready for takeoff. Finally.”

  “As soon as I know what the Pak scouts are doing. Twelve hours, I promise.”

  In the ‘scope screen the Pak scouts showed as tiny green lights, a good distance from each other, and measurably closer t
o Sol. Brennan seemed to know just where to find them, but then he’d been observing them for two months. “Still making three gravities,” he said. “They’ll be at rest when they reach Sol. I’ve been right about them so far. Let’s see how far I can carry it.”

  “Isn’t it about time you told me what you’ve got in mind?”

  “Right. We’re leaving the Flying Dutchman, now. The hell with convincing them I’m coming from Van Maanen’s Star. They’re seeing us from the wrong angle anyway. I’ll take off for Wunderland at one point aught eight gee, hold for a month or so, then boost to two gee and start my turn away from them. If they spot me in that time, they’ll turn after me, if I can make them think I’m dangerous enough.”

  “Why,” he started to ask, before he remembered that one point aught eight was the surface gravity of Home.

  “I don’t want them to think I’m a Pak. Not now. They’re more likely to chase an alien capable of building or stealing a Pak ship. And I don’t want to use Earth gravity. It’d be a giveaway.”

  “Okay, but now they’ll think you came from Home. Do you want that?”

  “I think I do.”

  Home wasn’t getting much choice about entering the war. Roy sighed. Who was? He said, “What if two of them go on to Sol and the other comes after us?”

  “That’s the beauty of it. They’re still eight light-months apart. Each of them has to make his turn eight months before he sees the others make theirs. Turning back could cost them another year and a half. By then they may just decide I’m too dangerous to get away.” Brennan looked up from the screen. “You don’t share my enthusiasm.”

  “Brennan, it’ll be two bloody years before you even know if they’ve turned after you. One year for them to spot you, one year before you see them make the turn.”

  “Not quite two years. Close enough.” Brennan’s eyes were dark beneath their shelf of bone. “Just how much boredom can you stand?”

  “I don’t know.”

  “I can make you a stasis field capsule, using two of the radon bombs.”

  Ye gods, a reprieve! “Hey, that’s good. But you’d have to throw away the radon, wouldn’t you?”

  “Hell, no. I wouldn’t do it. I’ll just move two of the bombs up into the lifesystem and rig a metal shell between the generators.”

  Conscience smote him. “Look, do you feel the same way I do? About waiting, I mean. We could take turns on watch.”

  “Come off it. I could wait for Judgment Day without unfolding my hands, if I had a reason.”

  Roy laughed. The constant delays had really been getting to him.

  The stasis box was a soft iron cylinder seven feet long, welded to the shells of two radon bombs to give a total length of fourteen feet. They’d had to run it through the door linking the kitchen and the exercise room.

  It fitted Roy like a coffin. It felt like a coffin. Roy’s teeth clamped shut, holding words back, as he waited for Brennan to shut the curved hatch.

  It made a very solid sound.

  Are you sure this will work?

  Idiot. Home was settled this way. Of course it’ll work. Brennan would’ve thought he was a fool.

  He waited in darkness. He imagined Brennan finishing the welding, testing currents and circuitry and so forth before linking the switch. Then—he wouldn’t sense time passing. When the door opened would he foolishly ask, “Didn’t it work?”

  Gravity dropped suddenly on him from above. Roy hit the floor and stayed there. He grunted in shock and surprise. No need to ask: Protector was in flight, making three gravities easy.

  The hatch swung back. Brennan caught him under the armpits and lifted. His hands were hard as hatchet blades. He half walked, half carried Roy to a crash chair. He shifted his grip to Roy’s belt and slowly lowered him into the crash chair.

  “I’m not a cripple,” Roy grunted.

  Brennan reclined Roy’s chair. “You’ll feel like one.” He lowered himself into the other chair with the same care. “They bit. They’re coming after me. We’ve been doing two point one six gee for two years now. I kept it that low because I was afraid they’d think I could outrun them.”

  “Can you? How are they doing?”

  “I’ll show you.” Brennan played with the keyboard, and a starscape filled the screen. “This is two years action telescoped into ten minutes. You’ll see it better that way. Can you spot the Pak ships?”

  “Yah.” Three green dots, visibly elongated, visibly moving. Presently a brilliant white light—Sol—drifted on from stage left.

  “I got some parallax on them while they were making the turn. Low acceleration, but a fast turn, about the same turning radius as ours. I think the individual ships must have turned separately. Now they’re back in tandem, coming at us at five and a half gee.”

  “You guessed that almost on the nose.”

  “Remember, I spent several days with Phssthpok as my mentor. I figured a healthy Pak could take three gee forever, and six gee for five years, which would kill him. They knew their limits and designed for ’em.”

  Three green stars drifted toward Sol. Presently, one by one, they went out and came on again. Now their color was dimmer, yellower. Roy tried to sit up against his own weight, but Brennan’s hand pushed him back. “This is where they switched to acceleration mode.”

  Roy watched for another minute, but nothing happened, except that the green stars brightened slightly.

  “This is where we stand now. Those images are about a light-year away. The ships themselves would be two light-months closer, assuming they’ve been chasing us at constant acceleration. In a few months we’ll know whether any of them turned back. Otherwise the lead pair would reach us in about fourteen months ship’s time, except that at some point they’ll go into deceleration mode and see if they can hurt us with the backblast, which means it’ll take a little longer.”

  “Fourteen months.”

  “Ship’s time. We’re doing relativistic speeds. We’ll cover a lot more distance than that.”

  Roy shook his head. “It comes to me that you woke me just a bit early.”

  “Not really. I can’t think of anything they could do to me over this distance, but I’m not certain they haven’t thought of something. I want you awake and fully recovered if something happens to me. And I want these bombs back in the weapons pod.”

  “It sounds unlikely. What could they do to you that wouldn’t kill me too?”

  “All right, I had another reason for waking you. I could have rigged you a stasis box right after we left Kobold. Why didn’t I?”

  Roy felt tired. Gravity pulling blood from his brain? “I had to be trained. Trained to fight this ship.”

  “And are you in condition to fight? Like a pile of wet noodles you are! When things start happening I want you able to move.”

  He did feel like a pile of wet noodles. Hell. “All right. Shall we—?”

  “No chance. For today you just lie there. Tomorrow we’ll walk you around a bit. Pretend you’ve been sick.” Brennan glanced sideways at him. “Don’t take it so hard. Let me show you something.”

  Roy had forgotten that this was Phssthpok’s own control module, with a hull that could be made transparent at will. It startled him when the wall went invisible. Then he looked.

  They were moving that fast. The stars behind were red-shifted to black. Ahead, above, they were violet-white. And from the zenith they swept back like a rainbow: violet, blue, green, yellow, orange, red, in expanding rings. The effect was total; all of Protector’s interior partitions had turned transparent too.

  “No man has ever seen this before you,” said Brennan, “unless you count me a man.” He pointed. “There. That’s Epsilon Indi.”

  “It’s off to the side.”

  “We’re not headed for it directly. I told you, I’m planning to make a right angle turn in space. There’s only one place I can do it.”

  “Can we beat the scouts there?”

  “Barely ahead of the second ship, I th
ink. We’ll have to fight the first one.”

  Roy slept ten hours a day. Twice a day he took long walks, from the control room around the exercise room and back, an extra lap each day. Brennan walked with him, ready to reach out. He could kill himself if he fell wrong.

  It felt like he’d been sick. He didn’t like it.

  One day they threw the ram field constriction wide open, and—in free fall, protected from the oncoming gamma rays by the scintillating dome of the inner ram field—they moved the radon bombs back to their nests in the weapons pod. For those two hours Roy had his strength back, and he gloried in it. Then he was back in two point one six gee, a four-hundred-pound weakling.

  With Brennan’s help he worked out a calendar of events for the longest war on record:

  33,000 BC: Phssthpok departs Pak.

  32,800 BC: First emigration wave departs Pak.

  32,500 BC: Second emigration wave.

  X: Pak scouts.

  2125 AD: Phssthpok arrives Sol. Brennan turns protector.

  2340 AD: Kidnap of Truesdale.

  2341 AD, October: Discovery of Pak fleet.

  2341 AD, November: Departure of Flying Dutchman. Destruction of Kobold.

  2342 AD, May: Discovery of Pak scouts.

  2342 AD, July: Truesdale in stasis. Departure of Protector.

  At this point relativity would begin to screw up the dating. Roy decided to go by ship’s time, given that he would have to live through it.

  2344 AD, April: Pak ships sighted altering course.

  2344 AD, July: Truesdale out of stasis.

  HYPOTHETICAL

  2345 AD, September: Meet first Pak ships.

  2346 AD, March: Right angle turn (?) Lose Pak scouts.

  2350 AD: Arrive Home. Adjust calendars.

  Roy studied Home. Over many decades there had been considerable message laser traffic between Earth and Home. There were travelogues and biographies and novels and studies of the native life. Brennan had already read it all; at his reading speed he hadn’t needed anything like his two years head start.