“Yes.” He rubbed his eyes. “I’m sorry. I guess that isn’t so obvious, unless you study this stuff. Yes. The Moonseed is all the way through the Moon. I kind of knew it would be,” Henry said sadly. “The assumption of mediocrity. Jays Malone wasn’t looking for Moonseed, so from the point of view of the Moonseed he landed at random, but he found it anyway. If it was here, at Aristarchus, it was going to be everywhere…

“Geena, the Moonseed works in a fractal way. The same structure regardless of scale. Whatever rock it settles in, it sets up the same kind of infestation pattern through the structure. And if you slice off a small piece of that rock, you’ll find the same structure repeated on the smaller scale, and if you slice off a piece of that, the same again… Right down to the microscopic.” He shook his head. “You have to admire the design. Cold, simple, logical. Yet with time, with the most minimal of resources, it allows the Moonseed to infest a world. The Moonseed is adapted to the universe. Perhaps the Moonseed, not we, is going to be the true master of the future…”

“You know, I hate it when you talk like that. It’s a sign of your morbid personality.”

He looked surprised. “Morbid?”

“Sure. How often would you wake me at three a.m. full of angst about death and futility? Morbid, Henry, that’s you.”

“Well, I guess I have a lot to be morbid about.”

She studied the Moon image once more. “Here’s something not in your puffball rock.” She tapped the dark centre of the image.

He rubbed his eyes. “It’s a mass anomaly at the centre of the Moon.”

“A mascon?”

“No. More dense, relatively, than that. More regular.”

“Regular?”

“It shows plane surfaces. Evidence of internal structure. It’s tens of miles across; it must be very dense. The data’s a little patchy…”

“What is it?”

He paused before replying. “Geena, I didn’t come to the Moon just to find if the Moonseed is spread right through it. I knew that must be true, if a galoot like Jays Malone could land at random and pick up a sample at his feet. All this is just confirmation.”

“Then why?”

“I had to find out why the Moon continues to exist at all. Why doesn’t the Moonseed destroy the Moon, as it did Venus? Something here has to be suppressing it. Making it inert. Oh, probably the stuff near the surface went off long ago, under the action of sunlight, but the reaction, the spread of the Moonseed, was stopped. Like everything else on the Moon, the Moonseed infestation here is old; the surface activity finished long ago.”

“Are you saying that this thing, at the core of the Moon, is suppressing the Moonseed?”