"It is sad," said the girl at last, "that you can never return to the past. It is there that our science has utterly failed. Travel in time is but a one-way voyage."
"You mean, Ayna," Orth said slowly, "we can't carry back the knowledge of an atomic shield that will arrest the spread of sterility—that mankind must abandon his use of atomic power?"
"You cannot go back," smiled Ayna, putting her hand on his shoulder as she spoke. "But there is no need. In 1980—if our records are not too wrong—Eric Ensamoff discovered such a shield."
"Great!" cried Orth. "I won't mind being stranded here. There's Ivath to set right on his ancient history. There's your perfected civilization to study." He swallowed his tongue momentarily and recovered it.
"And then there's you, Ayna," he blurted. "You're...."
The girl slid her fingers across a toggle-switch in the wall. "No use letting all the worlds hear us," she said softly, "much less see us. You see, I was sent to interview you and get your reactions. All the world was watching while you explored."
Orth took the girl and pulled her closer. He studied her face. She smiled.
"Sure it's turned off?" he demanded. She nodded.
"Fine ... no, they don't need to see this reaction...."