Zeyk said, “Is this is the first time anyone’s done this?”

“No,” Sax said. “We did it a lot in Da Vinci.”

“It feels good! It’s not as cold as I thought it would be!”

“And if you walk hard,” Sax said, “you’ll warm up.”

They walked around a bit, careful of their footing in the dark. It was quite cold, no matter what Zeyk said. “We should go back in,” Nadia said.

“You should stay out and see the dawn,” Sax said. “It’s nice without helmets.”

Nadia, surprised to hear such a sentiment coming from him, said, “We can see other dawns. Right now we have a lot to talk about. Besides, it’s cold.”

“It feels good,” Sax said. “Look, there’s Kerguelen cabbage. And sandwort.” He kneeled, brushed a hairy leaf aside to show them a hidden white flower, barely visible in the predawn light.

Nadia stared at him.

“Come on in,” she said.

So they went back.

• • •

They took their masks off inside the lock, and then they were back in the refuge’s changing room, rubbing their eyes and blowing into their gloved hands. “It wasn’t so cold!” “The air tasted sweet!”

Nadia pulled off her gloves and felt her nose. The flesh was chilled, but it was not the white cold of incipient frostbite. She looked at Sax, whose eyes were gleaming with a wild expression, very unlike him— a strange and somehow moving sight. They all looked excited for that matter, stuffed to the edge of laughter with a peculiar exhilaration, edged by the dangerous situation down the slope in Burroughs. “I’ve been trying to get the oxygen levels up for years,” Sax was saying to Nazik and Spencer and Steve.

Spencer said, “I thought that was to get your fire in Kasei Vallis to burn hard.”

“Oh no. As far as fire goes, once you’ve got a certain amount of oxygen, it’s more a matter of aridity and what materials there are to burn. No, this was to get the partial pressure of oxygen up, so that people and animals could breathe it. If only the carbon dioxide were reduced.”

“So have you made animal masks?”

They laughed and went up to the refuge commons, and Zeyk set about making coffee while they talked over the walk, and touched each other on the cheek to compare coldnesses.

“What about getting people out of the city?” Nadia said to Sax suddenly. “What if security keeps the gates closed?”

“Cut the tent,” he said. “We should anyway, to get people out faster. But I don’t think they’ll keep the gates closed.”

“They’re going out to the spaceport,” someone shouted from the comm room. “The security forces are taking the subway out to the spaceport. They’re abandoning ship, the bastards. And Michel says the train station— South Station has been wrecked!”