Garth’s eyes were glowing. “If we could reach that hangar, Doc, we could escape—all of us.”
“Sure. Only we can’t. Too many guards. It’s impossible to get out of this city. I’ve tried often enough. The only way I managed to survive was by entering the Darkness.” His voice trailed away.
“That black wall?”
“It’s a vibration-barrier. None of the Zarno can pass it. It shakes them to pieces—destroys them. The Ancients made it, I suppose, to guard their library.” Willard extended his hand in a sweeping gesture. “This is it. All the knowledge of the Ancients—tremendous knowledge—compiled here for reference. If we could only get it out to the world!”
Garth remembered something. “Does it mention their power-source?”
“Sure. I’ve had nothing to do for five years but study the library. I could put my finger on the wire-tape recording that explains the process. It’s an intricate business, but we could duplicate it on Earth easily enough.”
Paula would be glad to know that, Garth thought. The secret of the Ancients’ power, that could replace oil and coal—a vital secret to Earth now.
Willard was still talking. “I ran when I heard you coming. I’d been studying one of the recordings, but I thought the Zarno might have got through the barrier somehow. … It doesn’t harm humans, luckily, or the robots. I learned a lot in five years.”
“How did you manage to keep alive?”
“I found food. The Ancients had stocked up this place. Pills!” Willard grimaced. “They kept me alive, and there was a machine for making water out of the air. But I’m hungry for a steak.”
Garth scowled. “Doc—one more thing. You know what I mean?”
Willard sobered. “I get it, Ed. The cure. Whether or not I—”
“Whether or not you’ve found the cure for the Silver Plague. It hasn’t been checked yet. It’s still killing thousands on Earth.”
“So. I wondered a lot about that. Well—the answer is yes, Ed. I know the answer.”
“The cure?”
“Yes. I worked it out, completely, with the aid of the Ancients’ library. They were studying it too, but they didn’t have quite the right angle. However, they were able to supply the missing data I needed.” Willard took from his pocket a small notebook. “I had five years to work on it. So far, of course, it’s theoretical, but everything checks. It’s the cure, all right.”
Somehow Garth didn’t feel much excitement. Five years ago, he thought, that notebook would have saved Moira’s life. Now—well, it would still save life. It would save Earth. But—
He shrugged. “Two good reasons to get back to civilization. The cure, and the secret of the power-source.”
Willard nodded. “The Ancients died of the Silver Plague, indirectly. They tried to escape by changing their bodies. The library told me that.”
“Their bodies? How?”
“Well—you’ve seen the robots in Chahnn and here. Originally they were the servants of the Ancients.”
“Intelligent?”
“No—not in the way you mean. They could be conditioned to perform certain tasks, but usually they were controlled telepathically by the Ancients, who wore specialized helmet-transmitters for the purpose. The robots had radio-atomic brains that reacted to telepathic commands. Then when the Silver Plague struck, the Ancients tried to escape by transplanting, not their physical brains, but their minds. I don’t quite know how it was done. But the thought-patterns, the individual mental matrix, of each Ancient was somehow impressed on the radio-atomic brain of a robot. Their minds were put into the robots’ brains—and controlled the metal bodies. So they escaped the Plague. But they died anyway. Human, intelligent minds can’t be transplanted successfully into artificial bodies that way. So—in a hundred years—they were dead, all of them.”
So that was the secret of the Ancients’ disappearance from Ganymede. They had taken new bodies—and those bodies had killed them through their sheer alienage.
Willard crushed out his cigarette-stub. “All the knowledge of the Ancients at my fingertips, Ed. You can imagine what research I’ve done!”
“I should have thought you’d have looked for a weapon against the Zarno,” Garth said practically. “The Ancients were able to conquer them.”
“I did—first of all, after I’d learned how to work the recording-machines. A certain ray will destroy them—a vibrationary beam that shakes them to pieces, disrupts their molecular structure. The only trouble is—” Willard grinned sardonically. “It takes a damn good machine shop to build such a projector.”
“Oh. We couldn’t—”
“We couldn’t. The Ancients left plenty of apparatus here, but not the right kind. Mostly records, and a lot of robots. Sorry, Ed, but unless you brought good weapons with you, you’re stuck here with me.”
Garth looked around to where his companions were standing motionless. “Yeah. Looks like it. Unless we can break through to that hangar of antigravity ships—”
“We can’t. The city’s full of the Zarno, day and night. And there are always guards outside.”
Garth sighed. “The trouble is, unless we get out, nothing can stop the Silver Plague. Not to mention the fuel shortage. Wait a minute. You said the Zarno were superstitious—we tricked them once with a fake ceremony. Couldn’t we try that again?”
“I did,” Willard told them. “It didn’t work. The Zarno know what human beings are like now. Only the gods would impress them—those robots who once were their masters.”
Garth stopped breathing for a moment.
“There’s a way,” he said.
Willard looked at him. “I don’t think so. When I saw you’d come back, I hoped for a minute—but it’s no use. The Zarno are invulnerable to any weapons we can create here. We can’t get out of the city!”
“You said the gods would impress them.”
“The gods are dead—the Ancients.”
“Suppose one of them came back?”
Willard caught his breath. “What do you mean?”
“Originally the robots were controlled telepathically. Why can’t that work now—for us?”
“Don’t you imagine I thought of that? But it’s no use, without one of them helmet-transmitters. And there aren’t any. …” Willard sucked in his breath. “Hold on! I’d forgotten something. There’s one transmitter left—just
