But Prill had a map. The city of her birth was directly to starboard. She persuaded a man to join her, and they started walking.

They traded on their godhoods. Eventually they tired of one another, and Prill went on alone. Where her godhood was not enough, she traded small quantities of the youth drug, if she had to. Otherwise -

"There was another way in which she could maintain power over people. She has tried to explain it to me, but I do not understand."

"I think I do," said Louis. "She could get away with it, too. She's got her own equivalent of a tasp."

She must have been quite mad by the time she reached her home city. She took up residence in the grounded police station. She spent hundreds of hours learning how to work the machinery. One of the first things she accomplished was to get it airborne; for the self-powered tower had been landed as a safety precaution after the Fall of the Cities. Subsequently she must have come close enough to dropping the tower and killing herself.

"There was a system for trapping drivers who broke the traffic laws," Nessus finished. "She turned it on. She hopes to capture someone like herself, a survivor from the Fall of the Cities. She reasons that if he is flying a car, he must be civilized."

"Then why does she want him trapped and helpless in that sea of rusted metal?"

"Just in case, Louis. It is a mark of her returning sanity."

Louis frowned into the cell block below. They had lowered the bird's carcass on a ruined metal car, and Speaker had taken possession. "We can lighten this building," said Louis. "We can cut the weight almost in half."

"How?"

"Cut away the basement. But we'll have to get Speaker out of there. Can you persuade Prill?"

"I can try."

CHAPTER 22 — Seeker

Halrloprillalar was terrified of Speaker, and Nessus was leery of letting her out of the influence of the tasp. Nessus claimed to be jumping the tasp on her every time she saw Speaker, so that eventually she would welcome the sight of him. Meanwhile they both shunned the kzin's company.

So it was that Prill and Nessus waited elsewhere while Louis and Speaker lay flat on the floor of the observation platform looking down into the gloom of the cell block.

"Go ahead," said Louis.

The kzin fired both beams.

Thunder boomed and echoed within the cell block. A brilliant point the color of lightning appeared high on the wall, just beneath the ceiling. It moved slowly clockwise, leaving a redly glowing trail.

"Cut chunks," Louis directed. "If that mass lets go all at once, we'll be shaken loose like fleas on a shaven dog."

Speaker obligingly changed the angle of his cutting.

Still, the building lurched when the first chunk of cable and construction plastic fell away. Louis hugged the floor. Through the gap he saw sunlight, and city, and people.

He did not have a view straight down until half a dozen masses had been cut loose.

He saw an altar of wood, and a model of silvery metal whose shape was a flat rectangle surmounted by a parabolic arch. It was there for an instant, before a mass of cell block structure struck next to it and splashed fragments in all directions. Then it was sawdust and crumpled tinsel. But the people had fled long since.

"People!" he complained to Nessus. "In the heart of an empty city, miles from the fields! That's an all-day round trip. What were they doing there?"

"They worship the goddess Halrloprillalar. They are Prill's food source."

"Ah. Offerings."

"Of course. What difference does it make, Louis?"

"They might have been hit."

"Perhaps some of them were."

"And I thought I saw Teela down there. Just for an instant."

"Nonsense, Louis. Shall we test our motive power?"

The puppeteer's flycycle was buried in a gelatinous mound of translucent plastic. Nessus stood alongside the exposed control panel. The bay window gave them an imposing view of the city: the docks, the flat-sided towers of the Civic Center, the spreading jungle that had probably been a park. All several thousand feet below.

Louis struck an attitude: parade rest. An inspiration to his crew, the heroic commander stands astride the bridge. The damaged rocket motors may explode at the first touch of thrust; but it must be tried. The kzinti battleships must be stopped before they reach Earth!

"It'll never work," said Louis Wu.

"Why not, Louis? The stresses should not exceed -"

"A flying castle, for Finagle's sake! I only just realized how insane the whole thing is. We must have been out of our minds! Tootling home in the upper half of a skyscraper -" The building shifted then, and Louis staggered. Nessus had started the thruster.

The city drifted past the bay window, gathering speed. Acceleration eased off. It had never been higher than a foot per second squared. Top speed seemed to be about one hundred miles per hour, and the castle was rock steady.

"We centered the flycycle correctly," said Nessus. "The floor is level, as you will note, and the structure shows no tendency to rotate."

"It's still silly."

"Nothing that works is silly. And now, where shall we go?"

Louis was silent.

"Where shall we go, Louis? Speaker and I have no plans. What direction, Louis?"

"Starboard."

"Very well. Directly starboard?"

"Right. We've got to get past the Eye storm. Then turn forty-five degrees or so to antispinward."

"Do you seek the city of the tower called Heaven?"

"Yes. Can you find it?"

"That should be no problem, Louis. Three hours flying time brought us here; we should be back at the tower in thirty hours. And then?"

"Depends."

The picture was so vivid. It was pure deduction and imagination, yet — so vivid. Louis Wu tended to daydream in color.

So vivid. But was it real?

It was frightening, how suddenly his confidence in the flying tower had leaked away. Yet the tower was flying. It didn't need Louis Wu to make it go.

"The leaf-eater seems content to follow your lead," said Speaker.

The flycycle hummed quietly to itself a few feet away. Landscape flowed past the bay window. The Eye storm was off to the side, its gray gaze large and daunting.

"The leaf-eater's out of his mind," said Louis. "I take it you've got better sense."

"Not at all. If you have a goal, I am content to follow you. But if it may involve fighting, I should know something about it."

"Um."

"I should know something about it regardless, in order to decide whether it will involve fighting."

"Well put."

Speaker waited.

"We're going after the shadow square wire," said Louis. "Remember the wire we ran into after the meteor defenses wrecked us? Later it started falling over the city of the floating tower, loop after loop, endlessly. There should be at least tens of thousands of miles of it, more than we could possibly need for what I've got in mind."

"What do you have in mind, Louis?"

"Getting hold of the shadow square wire. Odds are the natives will just give it to us, if Prill asks politely, and if Nessus uses the tasp."

"And after that?"

"After that, we'll find out just how crazy I am."

The tower moved to starboard like a steamship of the sky. Starships were never so roomy. As for ships of the air, there was nothing comparable in known space. Six decks to climb around in! Luxury!