Eventually, well past midnight, she got up, stepped over sleeping bodies on her way to the bathroom, and splashed her face with lukewarm water. Instead of going back to bed she went to the window, where Turk was sitting in a chair keeping the night watch.

"Can't sleep," she whispered.

Turk kept his gaze fixed on the street outside, a ghostly void by the light of the dust-dimmed moon.

Nothing was happening. The peculiar eruptions from the ashfall showed no sign of resuming. Finally he said, "You want to talk?"

"I don't want to wake anybody up."

"Come out to the car." Turk and Dr. Dvali had moved the car closer to the room, where it would be easier to keep an eye on. "We can sit there awhile. It's safe enough now."

Lise had not left the room since they arrived and the idea appealed to her. She was wearing her only pair of jeans and an oversized shirt she had borrowed from the Fourth compound. She pulled her shoes onto her bare feet.

Turk opened the door and eased it shut when they had stepped outside. The smell of the ash was instantly stronger. Sulfur, or something bitter like that—why did the ash smell like sulfur? Hypothetical machines grew in cold places, or so Lise had learned in school: distant asteroids, the frozen moons of frozen planets. Was there sulfur out there? She had heard of sulfur on the moons of, was it, Jupiter? The New World's solar system had a planet like that, a cold radioactive giant, far from the sun.

The wind had died with nightfall. The sky was hazy but she could see a few stars. Even when she was very young her father had loved to show her the stars. The stars need names, he would say, and together they would name them. Big Blue. Point of the Triangle. Or silly names. Belinda. Grapefruit. Antelope.

She slid into the front seat next to Turk.

"We need to talk about what happens next," he said.

Yes. That was undeniably true. She said, "The Fourths are taking Isaac west."

"Right. I don't know what they hope to accomplish."

"They think he can talk to the Hypothetical."

"Great—what's he going to say? Greetings from the human race? Please stop dropping shit on us from outer space?"

"They're hoping to learn something profound."

"You believe that?"

"No. But they do. Dvali does, at least."

"Fourths are generally pretty reasonable people, but would you put a bet on that outcome? I wouldn't."

It was like religion, Lise supposed. You didn't lay odds on the sacred, you just looked for it with an open heart and hoped for the best. But she didn't say that to Turk. "So what do we do when they take off for the desert?"

He said, "I'm thinking of going with them."

"You're—what?"