"Only it's not the map that's wrong, Miss Kitty," he said. "It is my field of knowledge, and I've seen those continental outlines hundreds of times. They always corresponded to the map ... before."
She looked at him without comprehension.
"Not only that," Sam Eade entered the conversation. "As soon as we were clear of the wreck, Lt. Harper took a fix on stars and constellations. He's an astrogator. He knows his business. And they were wrong, too. Just a little wrong, here and there, but enough. And even more than that. On a tight beam, I should have been able to make a connection with Earth headquarters on this set. And I haven't yet got communication, and we know there's nothing wrong with this set."
"Sam knows his business, too, Miss Kitty," Lt. Harper said. "If he can't get communication, it's because there isn't any."
She looked wide-eyed from one to the other. For once, she was more concerned with a problem than with concealing her ignorance about it.
"It means," the lieutenant said, as if he were answering a question she hadn't yet asked, "that the Earth we are returning to is not the Earth we left."
"I don't understand," she gasped.
"There's a theory," Lt. Harper answered slowly. "Heretofore it has been considered only a mathematical abstraction, and having no counterpart in reality. The theory of multiple dimensions." She looked at him closely, and in her habitual ambivalence of thought reflected that he sounded much more intelligent than she had suspected.
"I've read about that," she answered.
He looked relieved, and threw a quick look at Sam. Apparently he had underestimated her intelligence, too—in spite of all her degrees.