So, a replacement. Bait for Louis Wu, the current addict, the wirehead. Louiss hand crept into the hair at the back of his head, under the queue. Plug in the droud, let it trickle electric current down into the pleasure center… where was the socket?

Louis laughed wildly. It wasnt there! The autodocs nano machines had rebuilt his skull without a socket for the droud!

Louis thought it over. Then he took the droud. When confused, send a confusing message.

The Hindmost lay like a jeweled footstool, his three legs and both heads tucked protectively beneath his torso. Louiss lips curled. He stepped forward to sink his hand into the jeweled mane and shake the puppeteer out of his funk.

"Touch nothing!"

Louis flinched violently. The voice was a blast of contralto music, the Hindmosts voice with the sound turned up, and it spoke Interworld. "Whatever you desire," it said, "instruct me. Touch nothing."

The Hindmosts voice — Needles autopilot — knew him, knew his language at least, and hadnt killed him. Louis found his own voice. "Were you expecting me?"

"Yes. I give you limited freedom in this place. Find a current source next to—"

"No. Breakfast," Louis said as his belly suddenly screamed that it was empty, dying. "I need food."

"There is no kitchen for your kind here."

A shallow ramp wound round the walls to the upper floors. "Ill be back," Louis said.

He walked, then ran up the ramp. He eased around the wall above a drop of eighty feet — not difficult, just scary — and was in crew quarters.

A pit showed where the doc had been removed. Crew quarters were not otherwise changed. The plants were still alive. Louis went to the kitchen wall and dialed cappuccino and a fruit plate. He ate. He dressed, pants and blouse and a vest that was all pockets, the droud bulging one of the pockets. He finished the fruit, then dialed up an omelet, potatoes, another cappuccino, and a waffle.

He thought while he ate. What was his desire?

Wake the Hindmost? He needed the Hindmost to tell him what was going on… but puppeteers were manipulative and secretive, and the balance of power in the Repair Center kept changing. Best learn more first. Get a little leverage before he reached for the truth.

He dumped the breakfast dishes in the recycler toilet. He climbed around the wall, carefully. "Hindmosts Voice," he said.

"At your command. You need not risk a fall. Here is a stepping-disk link," and a cursor arrowhead showed him a spot on the floor of crew quarters.

"Show me the Meteor Defense Room."

"That term is unknown." A hologram window popped up in the portside wall. "Is this the place you mean?"

Meteor Defense beneath the Map of Mars was a vast, dark space. All the stars in the universe ran round an ellipsoidal wall thirty feet high, and the floor and ceiling. Three long swinging booms ended in chairs equipped with lap keyboards, and those stood black-on-black before the wall display.

Past the edge of the pop-up window, under a glare of light, knobby bones had been laid out for study. This was the oldest protector Louis knew of, and Louis had named him Cronus. In the far shadows stood pillars with large plates on top, mechanical mushrooms. Louis pointed into the window. "What are those?"

"Service stacks," the Hindmosts Voice said, "each made from several float plates topped by a stepping disk."

Louis nodded. The Ringworld engineers had left float plates all through the Repair Center. If you stacked them, theyd lift more. Adding a stepping disk seemed an obvious refinement… if you had them to spare.

Louis saw a boom swing across the starscape. It ended in a knobby, angular shadow.

All protectors look something like medieval armor.

The protector was watching a spray of stars. His cameras would be mounted on the Ringworld itself, maybe on the outside of the rim wall, looking away from the sun. He didnt seem aware that he was being spied on.

Louis knew better than to expect asteroids or worlds. Unknown engineers had cleared all that out of the Ringworld system. This drift of moving lights would be spacecraft held by several species. Now the view focused on a gauzy, fragile Outsider ship; now on a glass needle, a General Products #2 hull, tenant unknown; now a crowbar-shaped ARM warship.

Tunesmiths concentration seemed total. He zoomed on starscape occluded by a foggy lump, a proto-comet. Tiny angular machines drifted around it, marked by blinking cursor circles. A lance of light glared much brighter: some warships fusion drive. Here came another, zipping across the screen. No weapon fired.

The Fringe War is still cold, Louis thought. Hed wondered how long that could last. A formal truce could not hold among so many different minds.

The protectors arms jittered above the keyboard.

In the corner of Louiss eye, sunlight glared down. Louis spun around.

Above Needle the crater in Mons Olympus was sliding open, flooding the cavern with unfiltered light.

The linear accelerator roared; an arc of lightning ran bottom to top.

The crater began to close.

Louis turned back to the display. Looking over Tunesmiths shoulder, he watched fusion light flare from offscreen and dwindle to a bright point. Whatever Tunesmith had launched was already too far to see.

Tunesmith had joined the Fringe War!

A protector could not be expected to do nothing, even if the alternative was to bring war down on their heads. Louis scowled. Bram the protector had been crazy, even if supremely intelligent. Louis must eventually decide if Tunesmith was crazy too, and what to do about it.

Meanwhile this latest maneuver should keep the protector busy. Now, how much freedom had Louis been allotted? Louis said, "Hindmosts Voice, show me the locations of all stepping disks."

The Hindmosts Voice popped up three hundred and sixty degrees of Map Room. The Ringworld surrounded Louis, a ring six hundred million miles around and a million miles wide, banded in blue for day and black for night and broad fuzzy edges for dusk and dawn. Winking orange cursor lights were displayed across its face. Some were shaped like arrowheads.

This pattern had changed greatly since Louis had last seen it. "How many?"

"Ninety-five stepping disks are now in use. Two failed. Three were dropped into deep space and probes launched through them. The fleets shot them down. Ten are held in reserve."

The Hindmost had stocked stepping disks aboard Hot Needle of Inquiry, but not a hundred and ten! "Is the Hindmost building more stepping disks?"

"With his help Tunesmith has built a stepping-disk factory. Work proceeds slowly."

The blinking orange lights that marked stepping disks were thick along the near side of the Ringworld, the Great Ocean arc. The far side looked sparse. Two blinking orange arrowheads had nearly reached the edge of the Other Ocean. Others were moving in that direction.

The Other Ocean was a diamond shape sprawling across most of the width of the Ringworld, one hundred eighty degrees around from the Great Ocean. Two such masses of water must counterbalance each other. The Hindmosts crew had not explored the Other Ocean. High time, Louis thought.

Most of the stepping disks were clustered around the Great Ocean, and of those, most were in a tight cluster that must be the Map of Mars. Louis pointed at one offshore from Mars. "What is that?"

"That is Hot Needle of Inquirys lander."

Teela the protector had blasted the lander during their last duel. "Its functional?"

"The stepping-disk link is functional."

"What about the lander?"

"Life support is marginal. Drive systems and weaponry have failed."

"Can some of these service stacks be locked out of the system?"

"That has been done." Lines spread across the map to link the blinking lights. Some had crossed-circle verboten marks on them: closed. The maze was complicated, and Louis didnt try to understand it. "My Master has override codes," the Voice said.