"And you didn't kill each other."

  "No. Vampires have no minds, Louis Wu. A vampire protector starts fresh, intelligent from birth, bound by no preconceptions and no old loyalties or promises. If a hominid cannot choose a protector of her own species, a vampire must be her next best choice."

  *You'd have killed each other for the last tree-of-life root.* Louis didn't say it. He wasn't sure it was true. "You found the master protector. How? Why did you fight?"

  "We fought for who would best guard the Arch and all beneath."

  "But his record was good, wasn't it? Whole species must have evolved and died out during his time, but civilizations rose and flourished until --"

  "But we won, Anne and I." Bram turned away. "Hindmost, what progress?"

  Louis looked toward a skeleton standing in dimness. He had guessed who that must be. "How did you get to him? He was eighty thousand falans old, you said." Nearly a million Ringworld rotations. Twenty thousand Earth years. "All that time, and then there was you."

  "He had to come. Hindmost?"

  The puppeteer called down. "I have played the Meteor Defense on three targets. We will not see results for two hours. Three before the installation in the comet can observe and react. Any of the others have hours to move, but who can dodge a beam of light?"

  "Your opinion?"

  "My people prefer to achieve our aims by giving other species what they want," the Hindmost said.

  "Louis Wu, react."

  Louis answered. "You've started something you can't stop. You've attacked two war fleets, three if you count the Fleet of Worlds. Political structures get old and die, Bram, but information never gets lost anymore. Storage is too good. Somebody will be testing the Ringworld defenses for as long as there are protons."

  "Then the Arch must have a protector, for as long as there are protons."

  "At least one. Invaders wouldn't just take over territory. They'd fiddle and test and maybe ruin something, like the City Builders did when they took the attitude jets on the rim wall to make interstellar ships."

  The knobby man waited.

  "A vampire might be a mistake."

  "You have a vampire in place. To fight him might be a far more expensive mistake."

  When Louis said nothing -- still chewing his thoughts -- Bram fished something from his vest. It was carved wood, bigger than the flute he'd played earlier. The windsound was deeper, richer, with a drumbeat that was Bram's fingertips tapping the barrel of the thing. Soothing, despite Louis's irritation.

  Louis waited for the mournful tootling to stop. He said, "You need a meteor watch in the plane of the Ringworld. I don't know how to do that. The solar Meteor Defense can't fire on anything that's hiding under the Ringworld floor."

  "Come," Bram said. "Hindmost, come. We'll return later to see what has escaped us."

  The knobby man's hand felt like a handful of marbles, and his pull on Louis's good wrist was irresistible. Louis found himself walking rapidly away. He looked back once at bones in a stance of attack. Then Bram guided or pushed Louis onto the stepping disk.

  ***

  They flicked through into Needle's cargo space.

  The knobby man helped Louis strip the suit off inside out, careful of his injured arm, careful not to release spores that might have accreted on the surface. Where was the Hindmost?

  Bram led Louis onto the other disk, flicked them both through into crew quarters. At no time had Louis considered resisting. Bram was just too futzy strong.

  The protector knelt before a blank wall. "The puppeteer worked here to summon images into his own quarters. Let us see how well I observed him." He produced wooden picklocks and went to work.

  A diagram appeared: the map of the stepping disks.

  Then a view of WeaverTown.

  The Hindmost flicked in: lander bay, then crew cabin. "Forgive the delay," he said.

  "Were you testing my security? Hindmost, wake the Kzin now," Bram said. "Afterward I want a better view of the rim wall where the protectors are working. Send your refueling probe."

  The Hindmost glanced at readouts in the autodoc lid, touched something, and danced back as the lid lifted.

  The Kzin stood in one fluid motion, ready to take on an army.

  Now the knobby man was armed with flash and variable-knife, though Louis hadn't seen him move. Bram waited to see Acolyte relax, then asked, "Acolyte, will you bind yourself to me according to the terms of Louis Wu's contract?"

  The Kzin turned. His scars had disappeared and his hands looked fine. "Louis Wu, shall I do that?"

  Louis swallowed his reservations and said, "Yes."

  "I accept your contract."

  "Get out of the 'doc."

  Acolyte did. Bram led Louis to the big 'doc and helped him in.

  The Hindmost was busy elsewhere. Color-coded dots and rainbow arcs swirled and shifted in the captain's cabin, responding to the puppeteer's music. Suddenly he whistled in discord. "The probe!"

  "Speak," Bram said.

  "Look! The stepping disk is dismounted from my refueling probe! Wait --" The puppeteer tapped at the wall. The view from the partly submerged probe became a view from the cliffside webeye. "There! Look, there it is!"

  The teleport device that had been mounted on the probe's flank now lay flat on the riverbank beside the Council House.

  "Nobody's trying to hide it," Louis said. "The little disk in the nose with the deuterium filter, is *that* still in place?"

  The Hindmost looked. "Yes."

  "It's almost flattering. Someone wants me back."

  "Theft!"

  "Yeah, but leave it. What you'd better do is bring the probe here and mount another disk. Acolyte, the Hindmost will read you your contract. Don't harm either of these people. Wake me up when the 'doc is through with me. The kitchen wall has settings to feed a Kzin, and Bram here will be using it, too. Will you be all right?"

  "Yes."

  "Stet." With no small trepidation, Louis lay down in the coffin-shaped 'doc. The lid closed.

  Chapter 21 -

  Physics Lessons

  AIR SLED TRANSFER STATION, A.D. 2893

  They saw it days ahead: a black line against the vastly more distant starboard rim wall.

  Closer, the line became a tremendous and artificial silhouette rising above the desert: a raised platform with bumps clustered near the center.

  Closer yet, the Reds could see daylight under parts of the elevation. By then Warvia knew. It was the Night People's goal, and the Sand People's cemetery.

  They were traveling through a dry land. Sand wasn't good for the motor. There had been a hungry few days before they ran across the Sand People.

  The Sand People went muffled in pastel robes. Small, compact beasts drew their wagons in groups of twelve, and served as meat animals, too. Carnivores! Red Herders and Machine People rejoiced alike.

  They made gifts of the cloth they'd taken from the Shadow Nest. The Sand People killed two of their beasts to make a feast. The several species shared lore and stories as best they could. Only Karker spoke the trade language well enough to be understood, and everything had to be translated.

  Rishathra didn't require translation, only gestures. Without their robes, the Sand People were small and compact: as short as Gleaners, with broader torsos and lean arms and legs.

  Harpster and Grieving Tube kept to the payload shell.

  The cruiser departed at halfdawn.

  It made Warvia uneasy to know that the Ghouls below her driving bench were near starving. But their goal was in sight.

  They arrived in bright mid-afternoon.

  An ancient road half covered with sand rose
to the axis of the platform. Three arms splayed out from the center section at 120-degree angles. The arms were wedge-shaped platforms that floated unsupported.

  The center section was a forest of mooring posts, metal rails, pulleys, and ropes. The roofed buildings on this structure looked like afterthoughts. They were empty and sandblasted by time: warehouses, a banquet hall, an inn. Running through the axis was a deep well with clean water at the bottom.

  On one of the wide paths between buildings, the Sand People had laid out their dead. It looked as if they had been doing that for generations. There were hundreds of skeletons. A double handful at the hub end were more mummy than bone. A few were more recent yet.

  "Just as Karker said," said Sabarokaresh. "Warvia, did Karker tell you ...?"

  Warvia said, "Karker told me how to find a shrieker village. Sand People don't eat shriekers, but I told him we could."

  "You were guessing?"

  "Well, what choice? Antispin of the funeral place ..." Warvia waved to antispin, and then looked again. Not thirty paces paces [sic -- should be a single "paces"] away, the smooth plains became a jumble of mounds. It looked like a crumbling city in miniature.

  "We won't wake the Ghouls," Sabarokaresh decided. "Let them wake and follow their noses."

  So they set their wagon on the cemetery heights, not too close to the array of corpses, and went out to look over the shrieker village.

  ***

  It was not the strangest thing Warvia had seen, yet it was strange enough.

  Here on the flat plain were hundreds of squared-off mounds. It looked like a half-melted city as built by people a foot high. Every mound had a door in it. Every door faced out from the center of the city.

  When the vampire killers walked toward the mounds, an army poured out of the holes and took up station.

  The shriekers were of a size to make a day's meal, Warvia thought. Their faces were blunt. They came out on all fours, then stood upright to display outsize claws intended more for digging than fighting, and shrieked. The high pitch hurt Warvia's ears.

  "Sticks," Forn suggested.

  Tegger waved it off. "If we just wade in and start clubbing them, they'll swarm us. There's a forest of ropes where we left the wagon. Didn't I see a net there?"

  ***

  The guard took station again to defend their city. Barok and Tegger threw the net. It was of strong, coarse weave, intended to lift cargo. Most of the guard crawled out and attacked. The Reds and Machine People ran then, pulling the net behind them, and paused to flip it over, to trap the few remaining guards. The other shriekers stopped, shrieked at the invaders, and returned to their stations.

  Four big ones remained caught.

  The Reds had eaten, and the Machine People were cooking their catch, before shadow crossed the sun. The Night People emerged, looked about them, and followed their noses. Warvia and Tegger crawled into the payload shell to sleep.

  ***

  "Mummified, most of them," Harpster told them at the following halfdawn. "Too far gone even to carry as hardship rations. Most of them died old. Sand People seem to lead a good, healthy life. Never mind, there was a ..."

  "Herder," Grieving Tube finished for him. "Killed by his own beasts, I expect. We rarely starve."

  "Good," Warvia said.

  The sliver of sun was already too bright for the Night People. They sat under an awning while the others soaked up sunlight and waited for the morning to warm.

  "We asked the Sand People about this place," Foranayeedli said. "They grow up in its shadow, but they know nothing of it except as a burial place."

  "It's much more," Harpster said. "Our need now is to mount the cruiser and moor it tight. We'll need food for five days for all four of you --"

  Sabarokaresh said, "We leave you here."

  Warvia and Tegger had known this was coming. Warvia said, "We thank you for staying so long. We would have looked peculiar, Red Herders driving a Machine People cruiser. Have your plans changed?"

  "We return to port at our own pace. We'll buy our passage with stories and lore. We'll teach the tribes we pass among to make fuel." Barok squeezed his daughter's arm. "When finally we reach Machine People again, we'll have enough of bounties to make Forn a dowry."

  "For the lessons also, thank you," Tegger said carefully.

  The girl favored him with a lecherous smile. "You were easy to teach!" She glanced at her father. "Oh, there were things we never yet spoke of --"

  "Courting," Barok said.

  "Yes. Remember how to court," Foranayeedli said. "Most hominids have courting rituals. Don't try to guess what they are. Stick to your own. It keeps *you* comfortable, keeps *them* amused. Can you remember courting?"

  Warvia said, "A little."

  Tegger said, "We court briefly and negotiate first. I suppose other hominids consider us shy or cold."

  "Hmm, yes --"

  Grieving Tube said firmly, "Time runs short. We must mount the wagon. Barok, Forn, you'll help before you leave?"

  "We will. We've found livestock, too. What do you intend?"

  "The wagon must sit solidly on the vehicle at the end of the starboard platform."

  "Is that a *vehicle*?"

  It was one of three long floating platforms. Tegger might have taken it for a covered dance floor, tournament field, shooting range ... The roof was transparent. The floor was flat, and five times as big as the cruiser's wheelbase. Sturdy aluminum loops as big as his torso were recessed into the floor.

  They centered the cruiser on the platform. Harpster and Grieving Tube supervised from under the awning while the rest threaded rope through aluminum loops and over and around the iron payload shell. They used pulleys to put tension on the ropes, until it seemed no force beneath the Arch would cause the wagon to shift.

  They were done by midday. Barok and Forn began to gear up for their own journey.

  "You'll need food," Tegger said. "Shall we smoke some shriekers?"

  "Good. And I noticed something," Barok said. He led them to his find: a shallow tray three manheights long by two wide, with lines trailing from holes at the corners. He lifted it effortlessly.

  Warvia grinned. "Brilliant! You can tow it!"

  "Yes. But first ..."

  ***

  The shrieker guard emerged to form rank.

  First, the nets. They scooped up most of the guard, twisted the net and threw it aside.

  Then the four dipped the edge of their tray into the loose sandy dirt and pushed and wiggled and pushed until the tray slid in and under. When they pulled at the ropes, the corners of the tray came up. They had a section of shrieker city on a tray.

  The guard had been working their way free. What they saw maddened them. A swarm of them dug straight into the section of city on the tray, frantic lest it escape. The rest formed a crescent and screamed.

  Lifting it took all the strength of all four, but they only had to carry it thirty paces. Then ropes and pulleys lifted it to the cemetery heights, and sliding posts on rails took it the rest of the way. They set it down aft of the cruiser, and slid the tray out from under the dirt.

  Four shriekers still struggling in the net were pulled loose, killed, cleaned, and smoked over wood Barok pulled from a collapsed building. The Machine People drank as they worked, as much water as their bellies could carry. They left before halfnight.

  ***

  Warvia and Tegger talked to the Night People while they inspected the work.

  "Truly, we thought you, too, would leave us before now," Harpster said. He was looking to spinward of port, where Foranayeedli and Sabarokaresh were tiny shadows.

  The Sand People had mapped a path to other tribes. Traveling by ni
ght, the City Builders could bounce from one tent city to another until they were in green lands once again.

  And where, Warvia wondered, would two Red Herders be by then?

  Warvia explained: "Red Herders travel widely. Twenty daywalks is nothing. Where we settle, rumor and questions will catch us up. We make poor liars, Harpster. We must go farther. Best to do without the questions."

  Tegger said, "In twenty daywalks we've had rishathra with Machine People and Dryland Farmers and Sand People."

  Warvia remembered that her own experience was wider yet. Nobody spoke that truth, not even Harpster. He only gunned and said, "But not Weed Gatherers nor Ghouls. Picky!"

  Warvia's eyes dropped. She would rish, but not with a Ghoul, and Tegger wouldn't either.

  "But we acted without the encouragement of vampire musk," Tegger said. "There is a restlessness in us -- or me ...?"

  "Us," Warvia said firmly. "Mated we are, but no longer for each other alone. I don't doubt that we can return to our custom --"

  "But we must be far from the rumor of Red Herders who rished with every species along their path! We've nearly left the Machine People empire behind. A little farther --"

  Warvia said, "Five days, you said. How does this thing move?"

  The Ghouls were at work closing the aft end of the great crystal canopy. Warvia began to feel claustrophobic. It bothered her, how little she and Tegger knew of where they were going.

  She thought they would not answer; and then Harpster said, "Like this." He moved a lever that took both arms and a strong back. The platform detached from the dock.

  Motion was hard to see, it was so smooth, but the platform was clearly drifting away.

  "How far are you going?" Tegger asked.

  "Oh, easily farther than the rumors you're fleeing." Harpster grinned.

  Grieving Tube strode around the bulk of the wagon. "Is this Barok's work? He did well. Tegger, Warvia, we're going as far as the rim wall. We can drop you off at the next stop if you like, or you can come along and then leave us coming back."

  Tegger laughed incredulously. "You'll be dead of old age before you get to the rim wall!"

  "Next stop, then," Harpster said agreeably.