Willard nodded. "The controls are easy. A couple of push-buttons and a steering-lever. I'd got a few feet off the ground when a couple of Zarno jumped into the boat with me. They heaved me out and followed. The flying-boat went off to Mars or somewhere, I suppose—it kept on going straight up. But there are others. Only I've never been able to get at them. If I could have, I'd have headed for Oretown, pronto."
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."