Another straw in the wind: while Doob had been fumbling with Scape, he had overheard a brief snatch of conversation from the other end in which the South Asian kid had addressed Julia as “Madam President.” This seemed so odd that he was tempted to bring it up in conversation. But he knew what the answer would be: It was just a courtesy. Former presidents were always addressed thus. It didn’t mean anything. Why was he making a big deal about it? He would come off as some combination of uncouth and comically hypersensitive.

“Dr. Harris, as you know, I’m something of a fifth wheel around here, and so I want you to know I appreciate your taking any time at all out of whatever it is you are busy with to touch base,” Julia began.

“Not at all, Madam . . . Julia,” Doob said, and then, because this was a video connection, resisted the urge to slap himself.

She found that interesting but decided to overlook it. “I feel like a camp counselor here,” she said. “Of course, I was on top of every detail of the Arkitects’ work during the run-up. But to sit in the White House looking at PowerPoints is one thing. Actually to be here is quite another.”

This was quite obviously bait. Fully aware of what a sucker he was being, Doob said, “How so?”

“Well, of course the range of cultural perspectives is vast,” Julia said, “but, modulo that, I find a lot of uncertainty. A sense that all of the Arkies’ talents and energies are bottled up—like so many genies just waiting for someone to rub the lantern. They all so keenly want to help.”

“It is, of course, less than two weeks since the Hard Rain began,” Doob pointed out. “We have five thousand or so years left to go.”

“The Arkie Community is well aware of those numbers,” Julia remarked.

The Arkie Community. Wow. He had to admire the way she’d slipped that in.

“Julia, what’s the purpose of this call? Am I to understand that whatever answers I give you will then be somehow disseminated to the Arkie Community? Because we have an email list for such purposes. An email list that includes every living human being.”

“That list was most recently used two days ago. An eternity for bottled-up Arkies.”

“We have been just a tad busy with the New Caird expedition.”

“There is a lot of curiosity about that in the Arkie Community.”

“There’s a lot of curiosity about it here.”

“I mean about its purpose,” Julia said.

“How could its purpose be any clearer?” Doob asked. “Anyone who made it through the screening and the training required to become an Arkie”—which doesn’t include you, Julia—“will understand exactly what we are trying to do from an orbital mechanics standpoint.”

“Obtain the stupendous amount of water that will have to be expended in order to attempt the Big Ride gambit,” Julia said. “Yes, Dr. Harris, even I understand that.”

“Gambit? Really?”

“Do representatives of the GPop ever make much of an effort to reach out and acquaint themselves with the thoughts and perceptions of the AC?” Julia asked.

“The what?”

“The Arkie Community,” Julia explained, with the slightest roll of her eyes.

“At any given time, about ten percent of the Arkies are rotating through Izzy. You know this. It is the largest number we can accommodate.”

“I’ve talked to several who have experienced that rotation. They all report the same thing. As soon as one enters the privileged environment of Izzy, with safer conditions, more room to move about, better food, and greater exposure to senior staff, the GPop worldview seems so sensible. Which only accentuates the reentry shock upon being deposited back into one’s arklet.”

Doob bit his tongue.

Julia continued. “What about reversing the roles a little—sending members of the GPop on temporary home stays in randomly selected arklets?”

“What about it?” Doob asked. “What purpose would it really serve?”

“From a purely technocratic standpoint, perhaps none whatsoever,” Julia said. And left the rest of her thought unsaid.

“If I went on a ‘home stay’ in a random arklet, what would I learn that I can’t learn from Scape or Spacebook?”

“A great deal, since you don’t actually use those applications,” said Julia, her voice deepening in amusement.

“I’m a little busy trying to get New Caird home. Go ahead, tell me. What am I missing?”

Movement caught his eye across the table.

He looked up to see Luisa shaking her head. Then Luisa clamped her face between her palms, closed her eyes for a moment, and opened them again. Doob felt his face warming, and once again resisted the temptation to slap himself.

“There is a lot of ferment in the AC around alternative strategies,” Julia said, speaking briskly and authoritatively, as befit a woman who had just been anointed the spokesperson for said Arkie Community. “A fascinating school of thought is developing around the idea of making a passage through clean space to Mars.”

“Clean space?”

“Oh, I forget you haven’t been following the relevant discussion groups. Clean space is just what Tav has been calling the translunar zone, relatively free of bolides.”

“Tav? Tavistock Prowse?”

“Yes, you should have a look at your old friend’s blog occasionally.”

Tav had been sent up to Izzy a month before the White Sky, when someone on the ground had decided that social media was going to be the glue that would hold the Cloud Ark together and that Tav was just the man for that sort of thing.

“I’ve been busy,” Doob said. “But Tav ought to know that we have simulated and war-gamed the Mars option to within an inch of its life, and it’s just not a good idea.” He could see Julia formulating an objection that he didn’t have the patience to listen to. “Anyone who is seriously advocating we go to Mars is—” He didn’t want to say what he was thinking, which was smoking crack, and so he settled for “—not taking some of the practical realities into account. One solar flare at the wrong time could kill everyone.”

“Only if everyone goes.”

“If you’re talking about just sending a contingent to Mars, then you have to consider how much of our equipment and supplies they’ll be allowed to take with them.”

“I think many talented Arkies would volunteer to be part of a small, lean advance party. The lure of clean space is strong.”

“Well, we are not in what I guess Tav considers clean space,” Doob said. “We are in dirty space, and we have to focus on that reality, rather than woolgathering about trips to the Red Planet.”

“You needn’t remind me,” Julia began.

“Yes. You saw your friend and colleague Pete Starling get chowdered by a bolide. I did actually see your Spacebook post about that, Julia. It was most affecting. I sense a ‘but’ coming, however.”

“As the days go by without a serious incident, people begin to wonder how dirty space really is. Interest grows in the Dump and Run option. The White Sky now feels like ancient history. The Hard Rain is upon us. Every day brings a course correction or two, to avoid a major bolide, and a litany of minor events. But the death toll stands at—”

“Eighteen, as of ten minutes ago,” Doob said. “We just lost Arklet 52. See, I am keeping my ear to the ground.”

“I am sorry to hear that,” Julia said, “and I’ll bet the rest of the AC will feel the same way, once that news has been distributed to them.”

“It’s on a fucking spreadsheet, Julia. All you have to do is look at it. We don’t distribute news. This is not the White House.”

“But in many respects it behaves like the White House,” Julia said. “An orbiting White House unfettered by constitutional checks and balances. But at least the White House had a briefing room, a way of reaching out. I would be happy to . . .”

“Why are you even talking to me about this?” Doob asked. “I’m a fucking astronomer.” Then, a thought. “How many conversations like this one have you been having with other members of the GPop?” He’d been assuming that Julia had singled him out as special, but for all he knew she had a call list as long as her arm, organized by those assiduous youngsters in the background. “Ivy is temporarily in charge.”