“Good idea,” Sax said. “Perhaps a delegation to Earth as well.”

Casting seeds. It was just like on the moors; some would sprout, others wouldn’t.

He went looking for Ann, but found she had left Pavonis— gone, people said, to a Red outpost in Tempe Terra, north of Tharsis. No one went there but Reds, they said.

After some thought Sax asked for Steve’s help, and looked up the outpost’s location. Then he borrowed a little plane from the Bogdanovists and flew north, past Ascraeus Mons on his left, then down Echus Chasma, and past his old headquarters at Echus Overlook, on top of the huge wall to his right.

Ann too had no doubt flown this route, and thus gone by the first headquarters of the terraforming effort. Terraforming . . . there was evolution in everything, even in ideas. Had Ann noticed Echus Overlook, had she even remembered that small beginning? No way of telling. That was how humans knew each other. Tiny fractions of their lives intersected or were known in any way to anybody else. It was much like living alone in the universe. Which was strange. A justification for living with friends, for marrying, for sharing rooms and lives as much as possible. Not that this made people truly intimate; but it reduced the sensation of solitude. So that one was still sailing solo through the oceans of the world, as in Mary Shelley’s The Last Man, a book that had much impressed Sax as a youth, in which the eponymous hero at the conclusion occasionally saw a sail, joined another ship, anchored against a shore, shared a meal— then voyaged on, alone and solitary. An image of their lives; for every world was as empty as the one Mary Shelley had imagined, as empty as Mars had been in the beginning.

He flew past the blackened curve of Kasei Vallis without noting it at all.

• • •

The Reds had long ago hollowed out a rock the size of a city block, in a promontory that served as the last dividing wedge in the intersection of two of the Tempe Fossa, just south of Perepelkin Crater. Windows under overhangs gave them a view over both of the bare straight canyons, and the larger canyon they made after their confluence. Now all these fossae cut down what had become a coastal plateau; Mareotis and Tempe together formed a huge peninsula of ancient highlands, sticking far into the new ice sea.

Sax landed his little plane on the sandy strip on top of the promontory. From here the ice plains were not visible; nor could he spot any vegetation— not a tree, not a flower, not even a patch of lichen. He wondered if they had somehow sterilized the canyons. Just primal rock, with a dusting of frost. And nothing they could do about frost, unless they wanted to tent these canyons, to keep air out rather than in. “Hmm,” Sax said, startled at the idea.