“But that might cause real problems with Earth’s gravity. I think you need the months of the trip to get prepared for it.”

Sax nodded. “What you would need is a kind of exoskeleton. Inside it you’d feel somewhat supported, and therefore as if in a lighter g, perhaps. Those new birdsuits I’ve heard of, they must have the capacity to stiffen to something like an exoskeleton, or you’d never be able to hold the wings in position.”

“An ever-shifting carapace of carbon,” Michel said with a smile. “A flowing shell.”

“Yes. You might be able to wear something like that to walk around in. It wouldn’t be so bad.”

“So first we move to Mars, you’re saying, where we have to wear walkers for a hundred years— then when we have changed everything, to the extent that we can sit out here in the sun only slightly freezing, then we move back to Earth, where we have to wear walkers again for another hundred years.”

“Or forever after,” Sax said. “That’s correct.”

Michel laughed. “Well, maybe I will go then. When it gets like that.” He shook his head. “Someday we’ll be able to do everything we want, eh?”

The sun beat down on them. The wind rustled over the tips of the grass. Each blade a green stroke of light. Michel talked about Maya for a while, first complaining, then making allowances, then enumerating her good qualities, the qualities that made her indispensable, the source of all excitement in life. Sax nodded dutifully at every declaration, no matter how much they contradicted the ones that had come before. It was like listening to an addict, he imagined; but this was the way people were; and he was not so far from such contradictions himself.

After a silence had stretched out, Sax said, “How do you think Ann sees this kind of landscape now?”

Michel shrugged. “I don’t know. I haven’t seen her for years.”

“She didn’t take the brain plasticity treatment.”

“No. She’s stubborn, eh? She wants to stay herself. But in this world, I’m afraid. . . .”

Sax nodded. If you saw all the signs of life in the landscape as contaminations, as a horrible mold encrusting the pure beauty of the mineral world, then even the oxygen blue of the sky would be implicated. It would drive one mad. Even Michel thought so: “I’m afraid she will never be sane, not really.”

“I know.”