The yellow sun dropped completely behind the north slope of the V notch and he went on to the caves. He found Craig and Anders, the only two who might know anything about Ragnarok’s axial tilts, and told them what he had seen.

“I made the calendar from the data John gave me,” Anders said. “The Dunbar men made observations and computed the length of Ragnarok’s year⁠—I don’t think they would have made any mistakes.”

“If they didn’t,” Lake said, “we’re in for something.”

Craig was watching him, closely, thoughtfully. “Like the Ice Ages of Earth?” he asked.

Lake nodded and Anders said, “I don’t understand.”