Building Harlequin’s Moon Read online

  Praise for Larry Niven, Brenda Cooper, and

  Building Harlequin’s Moon

  “Fans of both hard and softer, psychological SF will welcome veteran Niven and newcomer Cooper’s well-written tale of a 60,000-year layover in space. . . . Niven and Cooper provide complicated characters, particularly the AI, which struggle with realistic moral dilemmas.”

  —Publishers Weekly

  “Niven lifts the reader far from the conventional world—and does it with a dash.”

  —Los Angeles Times

  “Great storytelling is still alive in science fiction because of Larry Niven.”

  —Orson Scott Card

  “Larry Niven’s and Brenda Cooper’s colonization novel is a hugely ambitious, meticulously rendered feast for both head and heart. I can’t wait to see what they do next!”

  —Steven Barnes

  “One of our finest . . . [Niven] jams ideas for several novels into each one he creates.”

  —Chicago Sun Times

  “Larry Niven and Brenda Cooper have accomplished that most difficult of tasks, a novel full of real, hard science, but character-driven from the first page. The scope is enormous, but the focus is intimate, with characters who live and breathe. A marvelous read!”

  —Louis Marley

  “Niven and Cooper craft an entertaining epic with subtexts concerning cultural obsessiveness and the fear and worship of science.”

  —Booklist

  “Building Harlequin’s Moon is a big tale, well told. Wonderful world-building and characters you can care about.”

  —Syne Mitchell

  Tor Books by Larry Niven

  N-Space

  Playgrounds of the Mind

  Rainbow Mars

  Scatterbrain

  Ringworld’s Children

  WITH STEVEN BARNES

  Achilles’ Choice

  The Descent of Anansi

  Saturn’s Race

  WITH JERRY POURNELLE AND STEVEN BARNES

  Destiny’s Road

  Beowulf’s Children

  WITH BRENDA COOPER

  Building Harlequin’s Moon

  WITH EDWARD M.LERNER

  Fleet of Worlds

  Juggler of Worlds*

  *Forthcoming

  BUILDING

  HARLEQUIN’S

  MOON

  LARRY NIVEN

  AND BRENDA COOPER

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  This is a work of fiction. All the characters and events portrayed in this book are either products of the author’s imagination or are used fictitiously.

  BUILDING HARLEQUIN’S MOON

  Copyright © 2005 by Larry Niven and Brenda Cooper

  All rights reserved.

  A Tor Book

  Published by Tom Doherty Associates, LLC

  175 Fifth Avenue

  New York, NY 10010

  www.tor-forge.com

  Tor® is a registered trademark of Tom Doherty Associates, LLC.

  ISBN-13: 978-0-7653-5129-6

  ISBN-10: 0-7653-5129-3

  First Edition: June 2005

  First Mass Market Edition: April 2006

  Printed in the United States of America

  0 9 8 7 6 5 4 3

  TO THE MEMORY OF ROBERT FORWARD

  ACKNOWLEDGMENTS

  FROM BRENDA:

  I’d like to thank Larry Niven for taking on this project with me. Larry has had a longtime rule against collaborating with amateurs, and since this is my first novel-length work, I definitely qualified, at least when we started. This has been a multiyear project. I’m sure there were times when he was ready to throw away the manuscript, but instead he just pointed out ideas and characters that needed work, and helped me through; most important, he always believed in me. His hands, ideas, and words are throughout this novel, but like every good teacher, he made me write my way out of most of my messes. Any messes left in here are mine alone. Thanks, Larry!

  Personal thanks as well to my family: to my dad, who explained the concept of mass multiple times, and asked about the book every time he talked to me (sure that I was doing great, even when I wasn’t); to my mom; my son, David; and daughter-of-the-heart Lisha; my partner, Toni; and to Cindy Ross and Joe Green. Thanks also to Marilyn Niven, for being supportive of this project.

  FROM BRENDA AND LARRY:

  Thanks to our agent, Eleanor Wood, for believing in this project, and for reviewing a very early draft and providing excellent suggestions. Thanks to Bob Gleason from Tor, our editor.

  Thanks to Yoji Kondo, the rocket scientist and science fiction writer who writes as Eric Kotani. We needed a pair of stars to fit our story—to become Apollo and Ymir—and Yoji found them for us.

  We’d both like to thank Steven Barnes, who introduced us, and has given us both many tools across many years. The Fairwood Writers read the whole novel in draft, and made many excellent suggestions. They are David Addleman, Darragh Metzger, John A. Pitts, Allan Rousselle, David R. Silas, Renee Stern, and Patrick and Honna Swenson. The members of the LARRYNIVEN-L list helped out with naming a planet. G. David Nordley spent time chatting with us about ship designs. We’d also like to thank the late Bob Forward for chats about this book, and for inspiring early star drive designs.

  BUILDING

  HARLEQUIN’S

  MOON

  Contents

  Prologue

  Part I: Selene

  Chapter 1 Teaching Grove

  Chapter 2 Leaving Home

  Chapter 3 Planting

  Chapter 4 The Controller

  Chapter 5 The Hammered Sea

  Chapter 6 Star Systems

  Chapter 7 Erika’s Folly

  Chapter 8 Wild Water

  Chapter 9 The Watcher

  Chapter 10 Mid-Winter Week

  Chapter 11 Transition

  Part II: Air

  Chapter 12 Space!

  Chapter 13 Curiosity

  Chapter 14 High Council

  Chapter 15 Skating

  Chapter 16 Meets And Bounds

  Chapter 17 Watching Rachel

  Chapter 18 Treesa

  Chapter 19 The Library

  Chapter 20 Dead Ends

  Chapter 21 Orders

  Chapter 22 The Summons

  Chapter 23 Sleeping Beauty

  Chapter 24 Waking Rachel

  Chapter 25 Catching Up

  Chapter 26 A Death in the Family

  Chapter 27 Finding Treesa

  Chapter 28 Homecoming

  Chapter 29 Harry

  Chapter 30 Mariner Stew

  Chapter 31 Journey

  Chapter 32 Reunited

  Chapter 33 Threat

  Chapter 34 Fighting Words

  Chapter 35 Fetching Refuge

  Part III: Fire

  Chapter 36 Fire

  Chapter 37 Aftermath

  Chapter 38 A Turn of Mind

  Chapter 39
Return to John Glenn

  Chapter 40 Erase/Rewrite

  Chapter 41 The Challenge

  Chapter 42 Changing Guard

  Chapter 43 History Class

  Chapter 44 Sea of Refuge

  Chapter 45 Picnic

  Chapter 46 Leaving

  Part IV: Water

  Chapter 47 Coming Home

  Chapter 48 Inside the Water Bearer

  Chapter 49 Landing Refuge

  Chapter 50 A Question of Life

  Chapter 51 Logistics Challenges

  Chapter 52 Reassignment

  Chapter 53 Vassal

  Chapter 54 Now I Lay Me Down to Sleep

  Chapter 55 Questions

  Chapter 56 Mid-Winter at Clarke Base

  Chapter 57 Jacob

  Chapter 58 Anger

  Chapter 59 Passage

  Chapter 60 Waking Gabriel

  Chapter 61 Leaving Safety

  Chapter 62 Honorable Choices

  Chapter 63 Suspicions

  Chapter 64 The Child

  Chapter 65 Searching

  Chapter 66 Landing Party

  Chapter 67 On Turtle Rock

  Chapter 68 Exercising Authority

  Chapter 69 The Choice

  Chapter 70 Exodus

  Chapter 71 Flare

  Chapter 72 Visits in Purgatory

  Chapter 73 The Half-Full Glass

  Chapter 74 Speaking From the Mount

  Chapter 75 Losing Ymir

  Part V: Renewal

  Chapter 76 Breaking Up

  Chapter 77 Liren

  Chapter 78 The Navigator

  Chapter 79 Going Cold

  Chapter 80 Celebration and Reconnection

  Chapter 81 Last Flight

  PROLOGUE

  CHAOS

  Year 894, John Glenn shiptime

  ERIKA WAS COLD and Gabriel was warm. She wouldn’t have been interested in this stuff anyway.

  Erika was one pilot of the carrier John Glenn. John Glenn was currently at rest, safely orbiting wide around the gas giant planet Harlequin, and not in need of a pilot.

  Gabriel headed the terraforming team, chartered to create a habitable moon from the jumble of raw material that made up Harlequin’s moon system. Four of the team were warm now, far too many in the long term; but during these few decades they would accomplish most of what needed doing. Then they would wait for the moon system to settle down again.

  The Large Pusher Tugs, all three of them, were thrusting hard against Moon Ten. Their fusion engines sprayed a trident of light across the sky. The lesser Moon Twenty-six was already in place, orbiting Moon One since last year. That orbit wasn’t stable—it shrank steadily within the cloud of impact debris around Moon One—but that didn’t matter. Moon Twenty-six would be gone in a few days.

  Gabriel sent: “John Glenn calling LPT-1. Wayne, how you doing?”

  “Nearly finished here, I think. Astronaut concurs. Check our orbit.”

  “I did that. Start shutting down the motors.”

  In four hours, Moon Ten was falling free.

  When this phase was over, Harlequin’s moons would have to be recounted. There would be fewer of them.

  Gabriel considered a meal and sleep. The moons wouldn’t collide for fifteen days yet . . . but he ordered a squeeze of stew and stayed at his post. One loose moon wouldn’t matter; there was no living thing to be harmed in Harlequin’s moon system, and minor accidents could be fixed. It was the LPTs he was worried about. Lose his spacecraft and he’d lose the game.

  The peppery smell of warming vegetables and broth made his stomach rumble.

  So. Where to park the pusher tugs?

  He smiled. They’d be passing very near Moon Forty-one.

  “Wayne? Bust your LPTs loose and get them into orbit. Here are the specs. I’m working out your next mission.”

  “When do we get some rest, boss?”

  “I’ll find you that too.”

  Gabriel ate slowly, savoring the celery and potatoes. John Glenn’s internal garden was thriving. It had been a water tank when they left Sol system, and their diet had palled rapidly.

  He had a plan. He could start on it tomorrow. Thrust would take a few hundred days. Harlequin would grow a little hotter; ultimately Moon One would too; and Erika, when she warmed, would love it.

  UNDER GABRIEL’S GUIDANCE, Wayne’s team lifted the Large Pusher Tugs from Moon Ten and set them drifting toward a rarefied region within Harlequin’s frantically busy moon system. Wouldn’t want them anywhere near the collision point.

  It took him and the Astronaut program less than an hour to work up the next sequence.

  The LPTs had tremendous acceleration when they weren’t attached to larger masses. Their light outshone the sun, Apollo, by a lot. By the end of the day they were in loose orbit around Moon Forty-one.

  Gabriel ate at his post while Wayne guided the LPTs to the surface, one by one. The hard part came next, as Wayne’s team moored them against the bedrock core. The tugs were flattened structures, a Tokamak-style fusion thruster ringing one side, a cage of shock absorbers and anchors at the other. Placing anchors was tricky, because when the LPTs were set going, their thrust would start quakes.

  Set them going on low thrust, let the blast backfire, they’d melt their way through volatiles down to bedrock. Then close the insulation ports and wait while the molten rock solidified over the next century. Gabriel’s team would spend a hundred years cold, then warm again to finish the job.

  But they’d finish adding volatiles and mass to Moon One before they went cold.

  ONE OF THE LAST major movements of a complicated symphony was under way as Moon Ten approached Moon Twenty-six, which was in motion retrograde above Moon One.

  There had been other collisions. Moon One was already a dust ball surrounded by a flattened ring that glowed in Apollo’s light. It looked like Saturn in Sol system, with the ring system lightly twisted by Harlequin’s massive gravity.

  The oblate spheroids drifted together like flaming taffy. Gabriel watched the two moons eat each other’s kinetic energy. Hot rock and volatiles churned in a twisting red-orange fireball and began to drift toward Moon One.

  A raw sense of power tugged at the edges of Gabriel’s attention as he forced his focus to stay narrow. He had to stay on top of this. Playing God carried awesome responsibility. His purpose was to create a habitable world, a staging area for the antimatter generator that would refuel the carrier John Glenn. That world, Selene, would need seas and gravity: more mass, more volatiles. Moon One must be built up.

  Selene also needed radiation shielding.

  Gabriel had been bashing moons together for more than three hundred fifty years, after many more years of research and simulation. Matters would have gone much faster in Ymir’s system, he thought, a trace of bitterness still edging his thoughts. John Glenn’s equipment wasn’t designed for Apollo system. He was supposed to have two more carrier ships and all their resources to help him. Hell, he was supposed to be someplace else entirely. Apollo’s inner rocky worlds were all missing, eaten as the gas giant Daedalus moved inward; anything he needed that wasn’t among Harlequin’s moons would have to be acquired from the Kuiper Belt. Comets were as far apart as they had been in Sol system, generally as far apart as the Sun from the Earth. Travel time expanded hugely. He was doing his damn best, but it was still taking forever.

  He stretched and twisted, working his body, pulling out as much tension as he could.

  Moons Ten and Twenty-six were history, a fireball above Moon One. Impacting like that, they’d turned a lot of their velocity into heat; but how much? The last time they tried this, with a different pair of moons, most of the mass from the collision had just dissipated. He’d look again in a hundred years.

  Time to go cold.

  AND WARM AGAIN, a hundred years later. He set to work.

  Moon One was lightly ringed. Most of the mass of a double lunar impact was gone. He’d watch Moon One for a while—or the Astronaut program
would—and presently he’d know if its mass had grown enough.

  John Glenn’s frozen sleep system had been altered according to specs in their last message from Sol system. This advanced process of being frozen didn’t just retard entropy; it rejuvenated. Gabriel felt wonderfully alive, though he sometimes pictured his life as a snake chopped up and scattered at random.

  And Erika’s life was scattered without regard for his or her own convenience. As a pilot, she would stay frozen for most of the next sixty thousand years.

  Meanwhile, Gabriel had work to do.

  He revived his team. Moon Forty-one’s surface had cooled around the three LPTs. Wayne set them to thrusting against the moon’s core.

  The core wasn’t as stable as Gabriel wanted—no iron ball, just a jumble of heavier stuff—and Wayne held the thrust low. There were still tremors. Pumps fed dirty water ice from the moon into the tanks: reaction mass for the LPTs’ motors. Moon Forty-one wasn’t large. This phase would be over in a few years.

  Then—no point in going cold. He would wait out the next couple of years, and watch. Moon Forty-one would graze Harlequin’s atmosphere, turning vast kinetic energy into vast heat. The gas giant would eat the moon. Some of its mass would undoubtedly form a broad ring of debris. It would be a hell of a sight, and it would have other benefits.

  Selene—the inhabited world that Moon One would become—would need shielding from Harlequin’s radiation output. The ring would be chaotic for a time, and during the next, oh, fifty thousand years, it would block most of the gas giant planet from Moon One. But time and endless collisions would move the ring particles toward a common orbital plane. In sixty thousand years—when Selene calmed enough to be seeded with life—the ring would only block half the planet. A hundred thousand years later the ring would be as thin as Saturn’s, and nearly useless as a shield.

  But John Glenn would be gone by then, on its way to Ymir.

  Gabriel had decided to form the ring early. He’d give Selene sixty thousand years to lose some of its surface radiation, and Harlequin itself would have time to settle down after impact. Harlequin would grow hotter, of course. The sun Apollo was too far from the moon system to provide enough heat to warm Moon One. Some of Selene’s heat must come from a hotter Harlequin.