“Oh, this is just bull,” Petit protested. “For God’s sake. There are holes in this you can drive a Chevy through. We’ve also been to Mars. Mars is only eleven per cent of Earth’s mass. How come we didn’t destroy Mars too? And we know it’s on the Moon. How come the Moon hasn’t burst like a party balloon?”

“I don’t know,” Henry said, looking determined. “But I think that’s the key, Professor Petit. The Moon. The Moon is the key.”

Monica asked, “The key? To what?”

But Alfred was speculating again. “You know, you’re right, Dr Meacher. The only way the Moonseed can get to a planetary surface is through the action of intelligence.”

“Which means—”

“Maybe that’s the purpose of intelligence. Maybe we were meant…”

There was a moment of silence.

Petit laughed. “Alien nano robots manipulating history, eh? Is that what you’re going to tell the President? Should she go on TV with that? Admiral Bromwich, I intend to disprove this absurd scaremongering hypothesis, point by point.”

Henry nodded. “Do it. I’ll be there to applaud you.”

“But in the meantime,” the Admiral said, “we have to consider how to advise the President. And Dr Meacher, for all he’s a little swivel-eyed for my taste, is the only one coming up with any scenarios here.”

“Thank you,” Henry said drily.

Bromwich said, “I think we have to work on a worst-case assumption.”

Petit laughed. “The worst case being the end of the world. In an election year, too.”

Admiral Bromwich turned to Henry. “You’ve told me how bad this is going to get. Now tell me what we should do about it.”

“Three things,” Henry said. “We know we can slow the Moonseed down, if not stop it altogether, at least before it gets into the mantle.”

“How?”

“The structures it forms are fragile. They can be smashed, to put it bluntly.”

“We’ll bomb the shit out of it,” the Admiral said.

“And,” Petit said, “when you run out of bombs?”

“Then I’ll be on the White House lawn ripping it apart with my teeth and bare hands,” the Admiral said. “Where will you be? What else, Dr Meacher?”

Henry said, “Maybe we can come up with some kind of nano counter-agent.”

“I thought you said there was no hope of that.”

“I might be wrong. We have to try. But, no, I don’t think there is any hope.”

He let that hang in the air, for long seconds, maximizing its impact.

Monica studied Henry anew. He was the first to understand this, she thought. There must have been a time, right at the beginning, when only he knew this. Only he, of all the billions on the planet, could see the future. The unfolding of Moonseed logic: Christ, the end of the world. How must that have felt?