"The instructions," Kingsley whispered, but Gary frowned at him so fiercely that he lapsed into shuffling silence, his great hands twisting at his side, his massive head bent forward.

The red light blinked out and Caroline snapped on the sending unit and once again the room was filled with the mighty voice of surging power and the flickering blue shadows danced along the walls.

Gary's head swam at the thought of it… that slim wisp of a girl talking across billions of light-years of space, talking with things that dwelt out on the rim of the expanding universe, Talking and understanding but not perfectly understanding, perhaps, for she seemed to be asking questions, something about the equations she had written on the pad. The tip of her pencil hovered over the paper as her eyes followed along the symbols.

The hum died in the room and the blue shadows wavered in the white light of the fluorescent tube-lights. The red light atop the thought machine was winking.

The pencil made corrections, added notes and jotted down new equations. Never once hesitating. Then the light blinked off and Caroline was taking the helmet from her head.

Kingsley strode across the room and picked up the pad. He stood for long minutes, staring at it, the pucker of amazement and bafflement growing on his face.

He looked questioningly at the girl.

"Do you understand this?" he rasped.

She nodded blithely.

He flung down the pad. "There's only one other person in the system who could," he said. "Only one person who even remotely could come anywhere near knowing what it's all about. That's Dr. Konrad Fairbanks, and he's in a mental institution back on Earth."

"Sure," yelled Herb, "he's the guy that invented three-way chess. I took a picture of him once."

They disregarded Herb. All of them were looking at Caroline.

"I understand it well enough to start," she said. "I probably will have to talk with them from time to time to get certain things straightened in my mind. But we can always do that when the time comes."

"Those equations," said Kingsley, "represent advanced mathematics of the fourth dimension. They take into consideration conditions of stress and strain and angular conditions which no one yet has been able to fathom."

"Probably," Caroline suggested, "the Engineers live on a large and massive world, so large that space would be distorted, where stresses such as are shown in the equations would be the normal circumstance. Beings living on such a world would soon solve the intricacies of dimensional space. On a world that large, gravity would distort space. Plane geometry probably couldn't be developed because there'd be no such a thing as a plane surface."

"What do they want us to do?" asked Evans.

"They want us to build a machine," said Caroline, "a machine that will serve as an anchor post for one end of a space-time contortion. The other end will be on the world of the Engineers. Between those two machines, or anchor posts, will be built up a short-cut through the billions of light-years that separate us from them."

She glanced at Kingsley. "We'll need strong materials," she said. "Stronger than anything we know of in the system. Something that will stand up under the strain of billions of light-years of distorted space."

Kingsley wrinkled his brow.

"I was thinking of a suspended electron-whirl," she said. "Have you experimented with it here?"

Kingsley nodded. "We've stilled the electron-whirl," he said. "Our cold laboratories offer an ideal condition for that kind of work. But that won't do us any good. I can suspend all electronic action, stop all the electrons dead in their tracks, but to keep them that way they have to be maintained at close to absolute zero. The least heat and they overcome inertia and start up again. Anything you built of them would dissolve as soon as it heated up, even a few degrees.

"If we could crystallize the atomic orbit after we had stopped it," he said, "we'd have a material which would be phenomenally rigid. It would defy any force to break it down."

"We can do it," Caroline said. "We can create a special space condition that will lock the electrons in their places."

Kingsley snorted. "Is there anything," he asked, "that you can't do with space?"

Caroline laughed. "A lot of things I can't do, doctor," she told him. "A few things I can do. I was interested in space. That's how I happened to discover the space-time warp principle. I thought about space out there in the shell. I figured out ways to control it. It was something to do to while away the time."

Kingsley glanced around the room, like a busy man ready to depart, looking to see if he had forgotten anything.

"Well," he rumbled, "what are we waiting for? Let us get to work."

"Now, wait a second," interrupted Gary. "Do we want to do this? Are we sure we aren't rushing into something we'll be sorry for? After all, all we have to go on are the Voices. We're taking them on face value alone… and Voices don't have faces."

"Sure," piped up Herb, "how do we know they aren't kidding us? How do we know this isn't some sort of a cosmic joke? Maybe there's a fellow out there somewhere laughing fit to kill at how he's got us all stirred up."

Kingsley's face flushed with anger, but Caroline laughed.

"You look so serious, Gary," she declared.

"It's something to be serious about," Gary protested. "We are monkeying around with something that's entirely out of our line. Like a bunch of kids playing with an atom bomb. We might set loose something we wouldn't be able to stop. Something might be using us to help it set up an easy way to get at the solar system. We might be just pulling someone's chestnuts out of the fire."

"Gary," said Caroline softly, "if you had heard that Voice you wouldn't doubt. I know it's on the level. You see, it isn't a voice, really… it's a thought. I know there's danger and that we must help, do everything we can. There are other volunteers, you know, other people, or other things, from other parts of the universe."

"How do you know?" asked Gary fiercely.

"I don't know how," she defended herself. "I just know. That's all. Intuition, perhaps, or maybe a background thought in the Engineer's mind that rode through with the message."

Gary looked around at the others. Evans was amused. Kingsley was angry. He looked at Herb.

"What the hell," said Herb. "Let's take a chance."

Just like that, thought Gary. A woman's intuition, the burning zeal of a scientist, the devil-may-care, adventuresome spirit of mankind. No reason, no logic… mere emotion. A throwback to the old days of chivalry.

Once a mad monk had stood before the crowds and shook a sword in air and shrieked invective against another faith, and, because of this, Christian armies, year after year, broke their strength against the walls of eastern cities.

Those were the Crusades.

This, too, was a crusade. A Cosmic Crusade. Man again answering the clarion call to arms. Man again taking up the sword on faith alone. Man pitting his puny strength, his little brain against great cosmic forces. Man… the damn fool… sticking out his neck.