"Antimatter. Hindmost, that makes the Fringe War a lot more dangerous. The Ringworld is too fragile for this."

"Agreed."

"Whats he doing now?"

The shadow of a protector leapt from its chair, arced like a ballet superstar across the view of comets and warships, touched down at one focus of the elliptical room, and was gone.

A hand like a sackful of ball bearings closed on Louiss forearm. He spasmed like a man electrocuted. "Louis! Good, youre awake," Tunesmith said briskly. "Without you this would have been difficult. Hindmost, come out of there. Danger does not await our convenience. Louis, are you all right? Your heartbeat sounds funny."

Tunesmith was a young protector.

A Night People male of middle age had been lured into a cavern that grew tree-of-life. Tunesmith had emerged from his cocoon state a hundred and ten days ago: a tremendous mind demanding to be trained, in a hominid body hardened for endless war.

At first he must have satisfied himself with the Librarians incomplete knowledge, and Acolytes, and with what came in niggardly driblets from the Hindmost.

Tunesmith would not have begun his intrusions in any tentative fashion, Louis thought. The Hindmost might block that. Tunesmith must have built this heavy equipment and programmed it at his leisure, then set it moving all at once, after hed picked the Hindmosts locks.

Fait accompli: suddenly hes standing over the puppeteer in his own living quarters. Suddenly hes filleted the Hindmosts spacecraft and is removing components as a fisher guts a trout.

Protectors of any species would be manipulative. Intelligence was manipulative, wasnt it? A superior intelligence would want to control his teachers. Knock them off balance from time to time. The differences between ally, servant, slave, and sled dog blur when the difference in intelligence is great enough.

A moment ago Louis had been spying on a protector. Suddenly the protector was beside him, gripping his wrist.

Louis said, "Im fine. Much too young to have a heart attack."

The puppeteers heads and legs were buried under him.

"Work on him," Tunesmith said. "Im going to be busy."

"Two questions," Louis said, but the protector was gone.

The Hindmost eased a head into the open. No part of the neck showed, only eye and mouth.

Tunesmith could be seen sprinting about outside Hot Needle of Inquiry, working controls, then shouting into thin air. Heavy machinery began to move. The rebuilt hyperdrive motor was in motion. Unequal halves of the ships hull began to close. The top of the linear accelerator began to track across the underside of Mons Olympus.

The Hindmost whistled. "I was right! Hes—" The head ducked back under him. Tunesmith was back.

He stooped to work controls on the hidden stepping disk. Then he picked up the curled-up puppeteer, evading the hind leg as it lashed out. They weighed about the same, Louis guessed. "Louis, follow," he barked, and stepped forward and was gone.

Just for an instant, Louis Wu rebelled.

It was a test, of course. Would Louis Wu follow him without question? This was all just too familiar.

An alien mastermind bursts into Louis Wus life, assembles a crew, and hares off on a mission known only to the master. First Nessus, then the Hindmost, then the protector Teela Brown, then Bram, now Tunesmith, each chooses Louis Wu for reasons of convenience, drops him into the middle of a situation he doesnt understand, and runs him like a marionette. By the time Louis finishes playing catch-up, hes committed to something on the far side of sanity.

Piersons puppeteers were control freaks. A true coward never turns his back on danger.

Being a protector was all about control.

Where would he be, what would Louis Wu have done, by the time he knew anything?

The instant passed. If he didnt follow, hed be out of the action entirely. Louis stepped forward, onto a stepping disk that looked like the rest of the floor, and flicked out.

A flood of sunlight made him squint.

He stood on a high peak, on a stack of six float plates and a stepping disk. Tunesmith and the Hindmost stood below him on a translucent gray surface. Louis looked first for the Arch, to orient himself.

The Arch — the far side of the Ringworld — arced from horizon to horizon, broad above the haze at the spinward and antispin horizons, narrowing toward noon where it passed behind the sun. Louis hadnt seen the Arch in some time.

Fist-of-God Mountain loomed to port like a lost moon, poking far out of the atmosphere. Around its foot the land was more moonscape than desert, hundreds of millions of square miles of lifeless pitted rock. Fist-of-God was an inverted crater. A meteoroid had punched up through the Ringworld floor from underneath, hundreds of years ago. The blast had flayed soil from the high places, even this far away. Naked scrith was dramatically slippery.

Closer were silver threads of river and silver patches of sea, and the dark green tint of life gradually encroaching. The land below the hill was a broad jungle, and cutting through it, a river miles across.

"Watch your footing," Tunesmith said. Louis lowered himself carefully onto naked scrith.

It was worth remembering: beneath this shell of landscape was nothing but stars and vacuum. There would be no springs hereabouts, no groundwater, nothing to support life. No busybody to wander by, to fiddle with the controls on an abandoned service stack. Exposed as it was, this was an excellent hiding place for high-tech tools such as these.

Louis asked, "Are you going to explain whats going on?"

Tunesmith said, "Briefly. As a breeder I knew little but remembered a great deal. Coming out of my transition from breeder to protector, the first thing I was sure of was that the Ringworld is terribly fragile. I knew that I was reborn to protect the Ringworld and all its species.

"That has come in steps. I whiffed Bram, of course, and knew I had to kill him. I spent some time learning from the Hindmost and his library, and watching the Fringe War develop. Then for a time it seemed best to work alone or with a few Hanging People protectors. Now I must assemble a team."

"To do what?"

Tunesmith touched controls. The service stack lifted. Four float plates detached from the bottom and eased apart. Tunesmith boarded a stack of two, leaving one each for the puppeteer and the man.

The puppeteer was looking about him. He said, "Downslope, one could survive. Ringworld folk are generally hospitable to strangers. Tunesmith, you never accept my word when you can test it. Why do you involve me?"

"And for what?" Louis demanded.

Tunesmith floated off downslope. Louis and the puppeteer boarded and followed. The protectors voice carried easily. He spoke Interworld with no trace of accent, projecting his voice from deep in his belly, fearing no interruption, like a king.

"The Fringe War grows more intense. The ARM is using antimatter instead of hydrogen fusion to power their motors and weapons. Louis, the Ringworld cannot survive this. Something must be done."

"See if you can describe it!"

"Louis, to shape a plan I need to learn more. Did the Hindmost tell you of a courier ship? Of puppeteer manufacture, with an experimental drive—"

"Long Shot. Ive flown it. The warcats have it!" He hadnt called a Kzin a warcat in a very long time.

"Were going to take it back. We have time to recruit Acolyte," Tunesmith said.

They were nearing the edge of the jungle.

"Why would Acolyte join you?"

"I expect you will tell him to. Acolytes father sent him to you to learn wisdom."