The old survival instincts asserted themselves and there were marriages among the younger ones. One of the first to marry was Julia.

She stopped to talk to Prentiss one evening. She still wore the red skirt, now faded and patched, but her face was tired and thoughtful and no longer bold.

“Is it true, John,” she asked, “that only a few of us might be able to have children here and that most of us who tried to have children in this gravity would die for it?”

“It’s true,” he said. “But you already knew that when you married.”

“Yes⁠ ⁠… I knew it.” There was a little silence. “All my life I’ve had fun and done as I pleased. The human race didn’t need me and we both knew it. But now⁠—none of us can be apart from the others or be afraid of anything. If we’re selfish and afraid there will come a time when the last of us will die and there will be nothing on Ragnarok to show we were ever here.

“I don’t want it to end like that. I want there to be children, to live after we’re gone. So I’m going to try to have a child. I’m not afraid and I won’t be.”

When he did not reply at once she said, almost self-consciously, “Coming from me that all sounds a little silly, I suppose.”

“It sounds wise and splendid, Julia,” he said, “and it’s what I thought you were going to say.”

Full spring came and the vegetation burst into leaf and bud and bloom, quickly, for its growth instincts knew in their mindless way how short was the time to grow and reproduce before the brown death of summer came. The prowlers were suddenly gone one day, to follow the spring north, and for a week men could walk and work outside the stockade without the protection of armed guards.

Then the new peril appeared, the one they had not expected: the unicorns.