The four of them advanced on the machine. Gary fell into step with Caroline and looked at the girl's face through her helmet visor. "You look fagged out," he said.

"I am tired," she confessed. They walked a few steps. "We had so much to do," she said, "and apparently so little time to do it in. The Engineers sound as if they are getting desperate. They seem to think the danger is very near.”

"What I can't figure out," Gary told her, "is what we are going to do when we get there. They seem to be head and shoulders over us in scientific knowledge. If they can't work it out, I don't see how we can help them.”

Her voice was full of weariness as she answered him.

"Neither do I," she said, "but they seemed so excited when they found out who we were, when I described our solar system to them and told them that the race had originated on the third planet. They asked so many questions about what kind of beings we were. It took a lot of explaining to get across the idea that we were protoplasmic creatures, and when they finally understood that they seemed even more excited.”

"Maybe," suggested Gary, "protoplasmic beings are a rarity throughout the universe. Maybe they never heard of folks like us before.”

She wheeled on him. "There's something funny about it all, Gary. Something funny about how anxious they are for us to come, how insistent they are in trying to find out so much about us… the extent of our science and our past history.”

He thought he detected a quaver of fear in her voice. "Don't let it get you," he said. "If it gets too funny, we can always quit. We don't have to play their game, you know.”

"No," she said, "we can't do that. They need us, need us to help them save the universe. I'm convinced of that.”

She stepped quickly forward to help Kingsley.