The Ringworld’s edge was narrow. The probe rose a few hundred feet higher, and arced over. A puff of fusion flame halted its fall and set it drifting toward the shadowed back of a black wall that seemed to reach to the heavens.
It slowed. Hovered. The probe spat.
A window popped up to overlay the others. It showed the probe hovering on indigo flame; then the probe dropped away and it showed only starlight.
The Hindmost said, “I give you a webeye window beyond the rim wall.”
“We need a view from the underside. Get us that,” Bram commanded.
“Aye aye.” But the Hindmost was doing nothing.
“Hindmost!”
“The probe already has my instructions. Motors off. Rotate. I want a view.”
The probe was turning as it fell. The view turned: black rim wall, sunglare, starscape … a silver thread was shining against the star-spattered black below the falling probe.
“That!” Louis said. “See it? You need a burn or we’ll hit it.”
“Burn, aye aye.” A burst of woodwinds, then, “What is it?”
“Not a spaceport ledge, it’s too narrow.”
They waited through the lightspeed delay. The silver thread was growing larger, clearer. Now it seemed banded, like a silver earthworm. Eleven minutes …
The probe’s spin stopped. Window displays tremored: the probe was thrusting, flaring in X-ray light.
Nova light blasted through the hologram window.
Louis, with his arms thrown over his eyes, heard music from hell, then a voice that had lost all human traits. “My fuel source is destroyed!”
Bram’s voice was cool. “My concern is for the enemy that fired on us.”
“We are challenged! Arm me and send me through!” A bestial bellow, all madness. Acolyte’s idea of a distraction? Or are we locked in with a mad Kzin?
“Let me through to my cabin,” the Hindmost pleaded. “I must see what is still working.”
“What could be working? Your probe is destroyed and we are attacked, we are known. Could an invader react so quickly, or was that a protector?”
“The stepping disk at least should be safe.”
Louis opened his eyes. “Why?”
“I’m not a fool!” the Hindmost bleated. “I opened a stepping disk link as we crossed the rim. A plasma blast, kinetic weapons, any threat should go straight through.”
“Straight through to what?” Louis blinked. He was still seeing spots.
“I linked it to the stepping disk at the map of Mons Olympus.”
Louis laughed. It was probably too much to hope for, that a thousand Martians were setting a new trap when the stepping disk sprayed star-hot plasma over them, but heyyy …
Big claws closed on his shoulders; warm red meat breathed in his face. “We are at war, Louis Wu! This is not a time for distractions!”
Distractions. Stet. “Acolyte, go suit up. Get my suit, and a webeye sprayer, too, and my cargo disk stack, wherever Bram—Bram?”
“Dining hall aboard Hidden Patriarch,” Bram said.
“Hindmost, route him there first. Bram, get him some weapons. If we have a working stepping disk on the probe, we should use it.”
Bram said, “Go.”
The Hindmost rattled / chimed / bonged. Acolyte stepped and flicked out. The Hindmost stepped where the granite block had been and was gone, was in his cabin, his tongues licking out at what looked like an alien chess set but must be a virtual keyboard. One head rose to say, “We have a link. The stepping disk still operates.”
“Try the webeye sprayer,” Bram ordered.
“Spray what?”
“Vacuum.”
Eleven minutes later the blacked-out window lit again: a revolving starscape with a slow ripple to it. Louis could picture a webeye falling free through vacuum, spinning a little—was the probe spinning too?—drifting gradually away from the probe. And while the protector was worrying about the Kzin and trying to watch the puppeteer and all four hologram windows, Louis knelt above the stepping disk and lifted the edge.
A tiny hologram of glowing sticks rose just above the disk itself—the map of the stepping disk system. A larger display would have given him away, but the Hindmost had fixed that. Louis tapped his changes in quickly and pushed the rim down.
“Do you see?”
“Hindmost, explain to see me how we could have missed that until now!”
Bram and the Hindmost sure as tanj weren’t watching him. Louis turned.
As viewed through the free-falling webeye, the silver thread had become a silver ribbon with raised edges, a shallow trough not unlike a miniature of the Ringworld itself. Slender toroids arced over it.
Unmistakably, it was the transport system: the magnetic levitation track that ran along the top of the rim wall for a third of its length. Teela’s repair crew must have led it over the rim wall and down the outside.
Louis said, “Well, I haven’t been watching the rim wall for a good half year.”
“We should have looked closer,” the Hindmost said.
The silver rail swept past. Now there was only starscape. The fluttering webeye was below the Ringworld floor, falling into the universe.
Louis said, “I might have guessed. You, too, Bram. What else would Teela’s crew use to move their reclaimed ramjets?”
“The terminus is far to spinward, perhaps on a spaceport ledge. We’re in the wrong place to be looking for a factory.”
Stacked cargo plates flicked in, with pressure gear and a webeye sprayer added to Louis’s clutter. Louis shouldered the floating mass aside to leave room for Acolyte.
The Kzin flicked in wearing full pressure gear: concentric clear balloons and a fishbowl helmet. He tipped back the helmet and asked, “Are we ready?”
Louis gestured at a rippling starscape. “You don’t want to flick into that.”
Unexpectedly, the Hindmost said, “The link is still open and has stopped moving.”
Louis said, “What …
Bram snapped, “Sprayed with plasma flame, dropped for a thousand miles, and it still works? Improbable!”
Louis took the webeye sprayer off the stacked cargo plates. “Try it.”
Heads turned. They didn’t get it. Louis said, “Hindmost, I want to spray a webeye through the stepping disk link. Set me up. We’ll just see what it hits.”
The Hindmost whistled. “Try,” he said.
Louis sprayed a bronze net at the stepping disk and saw it vanish.
They waited. Acolyte used the time to take a shower. Thirty-five degrees of Ringworld arc: five and a half minutes in transit, and the same again before they’d see it arrive. Transfer booths didn’t work faster than lightspeed, and neither, it seemed, did stepping disks.
“Signal,” the Hindmost said as his other tongue licked out. A fifth window popped up.
They looked up at stars crossed by the rim wall. A fuzzy bulk at the edge might be the probe. A lousy view—but the probe wasn’t falling. It had landed on a tiny target, the maglev track.
Bram said, “Acolyte, take the sprayer. Go through. Spray us a camera where we might see something interesting. Return instantly and report. Don’t wait for danger. We know it’s there.”
Too fast. Louis was just beginning to pull his suit on. Acolyte would be gone before he was ready. He said, “Hold it. Bram, he’s got to be armed!”
“Against protectors already on site? I prefer Acolyte to be conspicuously unarmed. Acolyte, go.”
The Kzin flicked out.
Louis finished getting into his suit. They’d have eleven minutes to wait.
Did Chmeee really think an old man like him, Louis wondered, could restrain and protect an eleven-year-old Kzin male?
It had been four minutes, and something was in view.
They watched a dark blur moving around the blurred edges of the window, inspecting the probe at its leisure. Then suddenly it was clear and close, an elegant alien pressure suit with a bubble helmet, and a near-triangular face with a mouth that seemed to be all bone. A single fingertip came closer yet, and traced curves Louis couldn’t see. It had found the webeye.