“I felt I had no choice,” said Ponter, looking down, his own browridge shielding him from having to meet Selgan’s emerald eyes. “I felt I had to do it, but…”

“But you regret it now?”

Ponter was silent, staring at the room’s moss-covered floor.

“Do you regret it?”

“I—I’m not sure.”

“Would you do it again, if you had the moment to live over?”

Ponter snorted a laugh.

“What’s so funny?” asked Selgan, curiosity, rather than irritation, in his voice.

Ponter looked up. “I thought it was only physicists like me who engaged in thought experiments.”

Selgan smiled. “We’re not so different, you and I. We each seek to find the truth, to solve mysteries.”

“I suppose,” said Ponter. He looked at the smooth, gently curving wooden wall of the cylindrical room.

“You haven’t answered my question,” said Selgan. “Would you do it again, if you could?”

Ponter was silent for a time, and Selgan let him be silent, let him consider his answer. “I don’t know,” Ponter said at last.

“Don’t you? Or is it that you simply do not wish to say?”

Again, Ponter was silent.

“I want to help you,” said Selgan, shifting on his own saddle-seat. “That’s my only goal. I won’t judge you.”

Ponter laughed again, but this time it was a rueful laugh. “That’s the whole point, isn’t it? Nobody judges us.”

Selgan frowned. “What do you mean?”

“I mean, in that other world—that other Earth—they believe there is a…well, we have no word for it, but they call it God. A supreme, incorporeal being who created the universe.”

Selgan shook his head. “How can the universe have a creator? For something to be created, it has to have a beginning. And the universe didn’t. It has always existed.”