Each unit contained billions of floating, microscopic crystals. Each crystal, coated with a monomolecular metal film, was a dynode cell capable of receiving, storing, and discharging energy on its own wavelength.

The inventor filled it with knowledge and asked it the vital question. The Index answered: "The invention described is impossible."

The knowledge it called on was, of course, human knowledge.

To Duchane, on the other hand, the Index was invaluable. It grew until it occupied mile after square mile of precious Eron floor s.p.a.ce. Into it were fed the complete files of every Company office, the immense volumes of police reports, intimate data on every individual within the limits of the Empire....

Duchane didn't ask the impossible. The questions he asked were simple. But, sometimes, the answers were a little strange....

19.

DANGER BELOW.

"The Director?" Horn asked shakily.

"Wendre Kohlnar," the officer said. His face was puzzled and a trifle condescending. "Don't ask me why. I'm just obeying orders."

"Where is she?" Horn asked quickly. His eyes searched the room.

The officer shrugged. "Somewhere in Eron. I suspect that she's mad, but then everyone seems to be these days."

The elevator doors kept opening and closing behind Horn; armed men spread out around the room.

"The last time I saw her," Horn said, "she had just been captured by rebels-"

"Slaves," the man amended. "They seemed to have some connection with the Entropy Cult. They gave the Director a chance to talk, and she said she wanted to help. Oddly enough, they believed her. Even odder, they were right."

Half of the workers in the room, Horn had noticed, were dressed in the drab rags of the lower levels. "And you don't know where she's gone?"

The officer shrugged again as if the whims of the insane were beyond him. "She contacted me from here, gave me instructions to gather what loyal guards and technicians I could find, and told me how to get here through the Directors' private tubeway. When I arrived, she left by the same means."

Horn was silent. He felt Redblade and Sair staring at him curiously. "All right," he said quickly. "We're taking over. You'll tell your men that they'll take orders from us, Sair, Redblade, or myself. So will you. Let's get busy."

With the dozen technicians Horn had brought, the control room had close to a complete complement. Horn had the barriers raised and the doors opened. In a few minutes he was reunited with the main body of rebel troops. The control room, with its myriad circuits, indicators, communication facilities, and controls, became central command. Reports steamed in.

Ninety percent of the north cap was in the hands of the rebels. Only a few strong points of resistance remained. With the control room's flexibility, they would soon be reduced. Communication devices of several kinds brought coherence out of confusion. Barriers began to drop throughout the cap. In a few minutes, the opposition was isolated. Ventilators were closed, and firefighting gases were released. As the effectiveness of these measures became apparent, ideas for turning facilities into weapons occurred on every side.

But new forces kept arriving, and it was impractical to keep guards in every Tube room.

"Can't we stop them from coming?" Horn asked the casually efficient officer.

"We can't cut off the Tubes," he said. "Only a Director can do that with the main switch. But we can cut the power to the Tube rooms. The ships won't come out of the lock. The troops will have to climb through the personnel lock in s.p.a.cesuits. We can lock all doors, flood them with gas-"

"Good," Horn said quickly, cutting him off as his enthusiasm threatened to get out of hand. "As soon as our troops are out of the way, do everything you can think of. What about the south cap?"

"We cut off power to there as soon as I took over. Duchane's men were in control, but now we haven't been able to raise anyone for hours."

In half an hour, the north cap was in their hands as securely as it would ever be. Horn turned to Sair. "Eron's isolated. Now it's only a matter of dealing with the forces already here."

Horn felt a great weariness. After so long they had only taken the first step, important though it was.

Sair took a deep breath and turned to the gold-uniformed officer. "You said you were in touch with the south cap. Could you make a general hookup from here to broadcast to every receiver in Eron?"

He shrugged. "Of course. It will go out to every screen, public or private. But I can't guarantee how many are still in operation."

"Set it up," Sair said. "Let me speak to Eron."

In a few minutes, it was ready. Sair stood in a small cubicle surrounded by the round, blank, staring eyes of camera lenses.

"Yes," he began quietly. "You recognize me. I am Peter Sair, who has been called the Liberator. I am alive. I am on Eron. Forces under my command have just taken over the north Terminal cap and the control room. Eron is isolated. The Empire is doomed.

"It is right. It is just. It is past time. Once more, throughout the five-hundred-light-year radius of the Empire, men will be free to live as they wish, to choose their own paths, and to follow them to their own goals. It is not a simple thing, or an easy one, to be free. And it isn't simple or easy to break the power of an Empire without shattering that Empire to pieces.

"But it must be done. The framework of the Empire must not be destroyed; the Tubes are vital to the interstellar civilization that man must have if he is to be free and strong. Destroy Eron and the Tubes, and every world in the Empire will be isolated as Eron is now. Into this isolation, this power vacuum, will rush men greedy for power. If freedom survives at all, it will be an oddity, unstable and short-lived. Humanity will become not one race but many.

"That need not be. It must not be. Do not exchange one set of chains for many. You can have, instead, a loose union of free worlds held together by the Tubes. You can pa.s.s mutually agreeable regulations through elected representatives. You can trade freely with each other in what one world overproduces and another needs. You can exchange information, knowledge, and art, growing strong and wise together.

"It is a n.o.ble dream. We had it, in the Cl.u.s.ter- A dream? No. Its realization is before us. If only we are wise now, strong now. Now is the time to strike a blow for freedom and strike it well. You are not alone. All over the Empire men are fighting for the things you fight for now. But here, on Eron, the real decision will be made. Free men are counting on you.

"I call upon you then-all you who love freedom-to fight for it. But I call upon you, too, to fight wisely. Obey the commands of your leaders. If you have none, go where you can find them. Do not kill without reason; do not destroy wantonly. You have many blows to repay, but they are not the ones you should strike now. They are pointless; the future is yours. Eron is yours. Do not destroy what belongs to you.

"And you who still fight for the Empire-I call upon you to surrender. Lay down your arms. Your cause is lost. The Empire is dead. Your former allegiance will not be held against you. This is a new day. We are all born again, alike in heritage, alike in freedom. The galaxy is ours.

"For now-farewell. I will be with you soon."

He had stepped into the cubicle an old man. He had stood in front of the cameras, his head lifted, ageless, a symbol of man, free and unconquerable. He stepped out of it rejuvenated, his stride brisk and purposeful.

"What did you mean by that last sentence?" Horn asked.

"I'm going into Eron now. I'm needed there."

"How? Where? You-"

"How? By that private tubeway I saw below. Where? It doesn't matter much. I'll soon work myself to the place where I'm needed."

Horn saw that the old man's decision was unshakeable. "I'm going with you," he said firmly.

"Your place is here," Sair objected. "We can't afford to lose the north cap."

"You've forgotten one thing," Horn said quietly. "We don't know the secret of the Tubes. Without that-"

"We'll struggle along," Sair interrupted. "The Tubes won't fail. We can still use them. The Directors of Eron used them for centuries without knowing the secret. You said so yourself."

"I did," Horn said, "but did they? I keep remembering things. Tubes were activated all the time. Someone had the secret. Someone had to have it."

"SAIR!" The word thundered across the room.

Everyone turned. A screen had come to life on a distant panel. On it was the face of a middle-aged man, lined and worn but firm; over his head was a dark hood. Behind him was a scene of confusion: men shouting, running, talking, arguing, crossing the screen. It was familiar; it was a command center.

Beside the screen, a gold-uniformed technician was shocked. "I didn't do anything!" he blurted out. "It just started coming in."

The officer's eyebrows climbed toward his hairline. "Someone," he said, "has some unorthodox equipment."

Sair was already in front of the screen. "Turn down your volume," he said wryly. "It's a little loud."

The man turned to someone out of view and said something. He turned back. "Sair?" His voice was normal. "Sorry. Had to be sure I broke in. This is Entropy Cult headquarters. We've been coordinating the rebellion from here."

Sair did something with his fingers up close to his chest. On the screen, the man's eyes widened momentarily.

"Good!" he said. "We've been doing what we could. With the preparations we've made, that's been quite a bit. We've got duplicates of the controls over Eron that are in the control room you've captured. We've been closing fire doors, releasing extinguishers, cutting off water. The mobs have been the big problem, and they've calmed down since you spoke to them. I think we're over the hump."

"What's Duchane been doing?" Sair asked.

"The last we heard, he had his men in s.p.a.cesuits and was blasting holes in the skin. That's effective only in the top few levels, but it slowed us down. We lost touch with him a while ago. How soon can you reach here with your staff to take over?"

"I'm leaving now," Sair said. "How shall I come?"

"Directors' tubeway. Sixth emergency stop. Count the flickers. Palm the red spot after the fifth flicker."

Horn stepped in front of the screen. "Is Wendre Kohlnar there?"

"Yes," said the man; "somewhere."

"Where is she?"

The man in the hood glanced helplessly over his shoulder. "I don't know. There isn't time." He stared at something far to the left. "What?" he shouted. "Who's that-?"

The screen went blank.

"What's happened?" Sair said, alarmed.

"Try to get that connection reestablished," Horn told the officer. He turned to Sair. "I don't like it. That could have been an attack. If Duchane should get hold of the controls in the area, he might swing the battle yet."

"What can we do?" Sair asked.

"Act on the a.s.sumption that Duchane has captured it, get there as fast as we can with the best chance to retake it, and pray he didn't use poison gas." Horn turned to the officer. "What luck?"

"The screen was unlisted. If we've managed to trace it correctly, it's dead."

"Are there any air suits handy?" Horn asked.

The officer shook his head thoughtfully.

Horn turned to Redblade. "Get as many s.p.a.cesuits as possible out of the nearest personnel locks. And find me men who have fought in them."

As Redblade turned away quickly, Horn paused. Who could he leave in charge here? He looked toward Sair, but the old man shook his head, as if he had read Horn's mind.

"I'm going along," he said.

"We need fighters," Horn pointed out.

"You'd be surprised what I've learned and done in a long lifetime. I'm going."

There was no use arguing with him, and that left only one person to choose. "Redblade," Horn said. "You're in charge when I leave."

"Oh, no!" the pirate protested, shaking his bearded head defiantly. "I'm not missing out on-"

"You're the only one I can trust," Horn said quietly. The giant subsided. "Pick a dispatcher. As soon as I've left by the tubeway below, have him signal another car and send another man off. The men will press the gold disk, then watch five flickers of the red disk and press it. There'll be room for only one man at a time dressed in a suit. Understand?"

Redblade nodded. Horn turned and picked out a heavy suit from the growing pile on the floor. Redblade held it for him easily as he slipped into it. Just before Horn slipped on the left gauntlet, he slipped his unitron pistol into the slot provided in the right gauntlet. Horn wiggled his fingers to see if they worked easily. They did. The gun was ready. He was ready.

Five minutes later, the tube car slid to a stop. The door swung out. The corridor was stone and dimly lit. Horn stepped out quickly into the catacombs; he closed the stone door behind him. There was no one in sight.

To the right, the corridor darkened. Horn turned to the left. The corridor turned right within a few meters. There Horn found the first bodies; they were as ragged as the clothes they wore. Horn paused, held his breath, and brushed the intercom control on the front of his suit.

"... and how long we wear these things-" someone was protesting.

"Silence!" The inside of Horn's helmet roared. "Only orders and reports will be given. When the gas is dissipated-"

Horn cut it off and let out his breath. That was Duchane. Cautiously, he moved to another corner. Beyond it was the back of a s.p.a.cesuit. Horn ducked back quickly, breathing hard. A sentry. But he hadn't seen, and he couldn't hear.

Horn walked around the corner. This time the sentry was looking toward him. Through the helmet, his face was surprised. His mouth started to open; his right hand started up. Horn's hands were already against the suit's breastplate. One hand brushed the intercom off; the other shot the gun.

There was no noise. The man collapsed, his face still surprised. Horn felt the distant vibration of his fall. He flicked on his own intercom again. It was silent. He flicked it off.

Something tapped him on the back. Horn swung around, his gun pointing like an elongated index finger, and restrained himself from pulling the trigger. Sair's white hair gleamed through the helmet that faced him.

Horn looked to see if Sair's intercom switch was off; it was. He leaned forward and pressed his helmet against Sair's. "Stay here!" he ordered. "Wait until you've got a body of men. Then attack!"

"What are you going to do?"

"If the gas wasn't poisonous, I might be able to stop a slaughter."

"And Wendre is there, eh?"

"Yes," Horn admitted. "Now wait!"

He moved forward toward where the light slowly brightened. There was another guard. Horn caught him from behind, but he died the same way, silently. There were more of the ragged men on the floor; some of them had no marks on them, and others had their heads caved in.

Horn looked down at the man he had killed. The foot of his right boot was covered with blood and brains. Horn was glad he had killed him.

There was a wide doorway now and no more guards. Horn turned on his intercom again. There was a sighing, background noise; it was the breathing of many men.