Hu let the video run now, and they saw the arklet’s rear halo snag on the loose blanket and rip it away, exposing the Human Genetic Archive to the orange radiance of Earth’s atmosphere.

Ivy said, “If that thruster hadn’t fired at the wrong moment—”

Hu nodded. “Arklet 214 would have passed underneath with two meters to spare. Not a margin to be proud of. But it would have been enough.”

After a pause, Hu added, “The HGA’s thermal protection system could have been designed better.”

Another pause in which everyone else waited to see who would be the first to laugh. If it weren’t for dark humor, they’d have no humor at all.

Hu seemed to sense it. “What I mean is that it was engineered for normal thermal loads.”

“Meaning sunshine,” Dinah said.

“Yes. Not for radiant heat shining up from the atmosphere below it.”

“The same thing is true of many parts of Izzy, of course,” Markus said. “We are having thermal overloads all over the place now. Moira, what’s the damage?”

Dinah had to give Markus credit for a kind of finesse for the offhanded way he dropped the question in. Moira, who had been quiet through the whole meeting, took a moment to snap out of her reverie.

“Well,” she finally said, “as Hu said, the thermal protection system—”

“Was bad,” Markus said. “We know.”

“There was no backup system.”

Markus said, “Of course not. The cooling system for the HGA was the rest of the universe. We do not expect to have a backup system for the rest of the universe. We can rely upon it to be cold most of the time.”

“Because of the accelerated schedule, caused by the Eight Ball—”

“Stop,” Dinah said.

Everyone looked at her.

“Let’s get this over with,” she said. “Look. When I was fourteen, one of my dad’s mines collapsed and killed eleven employees. It was terrible. He never really got better. Of course, he wanted to know what had happened. It turned out to be a long story. One thing led to another, which led to another . . . the individual steps all made sense, but no one could have seen the whole thing coming. Of course, he still felt responsible, but he wasn’t, in any normal sense of that word.

“So here’s what happened,” Dinah went on. “Sean Probst started an asteroid mining company that sent up a bunch of cubesats and gathered a lot of data about near-Earth asteroids, which he kept secret. He took the database with him on his mission to Greg’s Skeleton. His radio got hit by a rock and destroyed, so he couldn’t communicate. At the last minute, when it was basically too late, he had the idea to look at the database. He learned about the Eight Ball. He alerted me, I alerted Doob, Doob alerted everyone else, and we pushed up the schedule for everything. Moira pulled the trigger on the project, which had been planned for over a year, to disperse the HGA samples to the arklets. Like every other project in the history of the universe, it went slowly at first because all kinds of snags came up. And not only that, but all of the Flivvers were spoken for and all of the space suits were busy, because of the Splurge. So not much got moved. It was obviously safer to keep the samples in cold storage in the HGA while all of these logistical problems got sorted out. The Splurge happened and a lot of random shit got launched in our general direction and made Parambulator light up like crazy. Arklets were getting cornered on a pretty regular basis. We almost lost a couple. Ivy and I took off in the Flivver to fetch Julia and probably added a lot of other noise and chaos to that problem. Then, the thing we just watched happened. Arklet 214 tore most of the badly designed thermal protection system off of the HGA and exposed it to the direct radiance of the Earth’s atmosphere. The samples all warmed up before replacement thermal protection could be jury-rigged. All of those samples have been destroyed. Right, Moira?”

Moira, apparently not trusting her ability to speak, nodded.

“Okay,” Dinah said. “So I think that what Markus is really asking is how many of the samples in the HGA actually got moved to safe cold storage in other locations before this happened. In other words, how many survived?”

Moira cleared her throat and said, in a faint voice, “About three percent of them.”

“Okay. I only have one other question,” Markus said. “Have you talked to Doob?”

“I’m sure he suspects,” Moira said, “but I have not officially broken the news to him. I wanted to be absolutely sure first.”

“Are you sure now?”

“Yes.”

Markus nodded and spent a few moments thumbing something into his phone. “I am inviting him to join me and Moira here immediately,” he said.

Everyone who was not Markus or Moira stood up to leave. Markus held up his hand to stay them. “Before you go, let me say something about the Human Genetic Archive that was lost.”

He then paused for effect, until everyone was looking at him.

“It was always bullshit,” he said.

Everyone took a moment to consider it.

“Are you going to tell Doob that?” Ivy asked.

“Of course not,” Markus said, “but the real purpose of the HGA was politics on Old Earth.”

“Is that what we’re calling it now? Old Earth?” Sal asked, fascinated.

“That’s what I am calling it,” Markus said, “in the increasingly rare moments when I actually think about it.”

“Thank you, Markus,” Moira said.

HE HAD KNOWN, OF COURSE. IZZY’S COMPLEXITY WAS SO GREAT AS to belie its tiny size: a few hundred people sorted into a volume the size of a few jetliners. News traveled fast. Everyone had known within a few hours that the Human Genetic Archive had been almost completely destroyed.

He was in the Tank with Markus and Moira. They were gazing across the table at him, patiently awaiting some kind of reaction.

“Look,” he finally said, “Doc Dubois is no more. That was a persona, you understand? Just an act. I’m a private person. I do not spontaneously emote. Especially when people are watching me and expecting it. A year from now, when I’m alone, when I least expect it, I’ll break down in sobs over this. But not now. It’s not that I don’t feel. But my feelings are my own.”

“I am very sorry that it happened,” Moira said.

“Thanks,” Doob said, “but let me say what all of us are thinking. Seven billion people died yesterday. Compared to that, the loss of some genetic samples is nothing. The embryo that Amelia and I created together, and that I brought up here with me . . . well, that was a special favor that J.B.F. granted me as an incentive to come up here. No one else got that kind of special treatment. It was unfair. I knew it. I accepted it anyway. So here we are.”

“Yes,” Markus said. “Here we are. Going forward—”

“But I’m not sure I agree with you,” Doob said, “that the HGA was so insignificant.”

Markus bridled his impatience and raised his eyebrows. Doob looked at Moira. “What was the term you used? Heterozygosity?”

“Yes,” Moira said. “The stated purpose of the HGA was to ensure a sufficiently diverse genetic basis for the human race.”

“Sounds important to me,” Doob said. “What am I missing?”

“We have tens of thousands of human genomes recorded in digital form. From all different parts of the world.”

“So there’s your heterozygosity. That’s what you’re saying,” Doob prompted her. “That’s why”—he glanced at Markus—“the HGA wasn’t really needed.”

“Yes, but there’s a but,” Moira said.

“Okay, what’s the but?”

“The digitized sequences, as I’m sure you’ll understand, are only useful so long as we have the equipment needed to transcribe them into functional chromosomes in viable human cells. By contrast, to make use of a sperm sample, all we need is a turkey baster and some lube. But to make use of a DNA sequence stored on a thumb drive, we need—”

“All of the equipment in your lab,” Doob said.