“Probably not a rock,” Henry said. “Violent volcanism is the best hypothesis.”

“You say,” David Petit said. Petit was a Nobel Prize winning chemist, a thickset man with a Brooklyn accent. “Others don’t agree—”

Bromwich snapped, “And is this where it will stop? With this Permian shit?”

“No,” Henry said. “Ultimately, the mantle infestation will be the most serious. When the Moonseed is spreading under the crust.”

“Why?”

Monica saw that Bromwich still didn’t understand.

“Because,” she said, “it will blow the crust off the planet.”

“Like Venus.”

“Yes, Admiral. Like Venus.”

Silence, briefly.

Henry brought up molecular structure charts and scanning microscope images. “We think we have a handle on how the Moonseed works. If not why. It primarily attacks basaltic rocks, particularly those rich in olivine.”

“Like the Earth’s mantle material.” That was Alfred. “And comet dust, and primordial debris.”

The Admiral asked, “Primordial?”

“Left over from the formation of the Solar System,” Alfred said. “Admiral, this thing feeds on the most basic rock suite in the universe. It is well adapted to conditions in this universe. More so than we are, in fact. We should have suspected the existence of this thing. Even logically deduced it.”

Henry said, “It appears to reassemble the crystalline structure of a mass of rock in a recursive form which—”

“In English, doctor,” Monica said.

He brought up another image. A slice of rock, the crystal structure picked out with false colour. A maze of dwindling tunnels, disappearing beyond the resolution of the “scope into some invisible centre, a heart of darkness, “It is changing the structure of the rocks it touches. Building something.” It was a kind of bootstrap process, Henry said. The manipulation of the outer layers of a crystal structure enabled the more detailed rebuilding of inner layers, which in turn enabled changes on a still smaller scale… and so on. Like waldos, Monica thought, each layer of miniaturization building the next level down, on to invisibility.

“There is a certain logic in this,” Alfred mused. “Between planets, where resources are scarce, one might expect an evolutionary drive of this type. Towards the very small — the utilization and building-in of complexity into even the smallest grains of matter available.”

David Petit, the chemist, locked his boxer’s hands behind his head. “Your qualifications are all in geology, Dr Meacher. True?”

“Yes.”

“Not in chemistry or particle physics or biology.”

“That’s true.” Henry was quite unfazed.

Petit stopped there, satisfied he had made his point. For now.

Alfred Synge said, “Of course maybe this isn’t some kind of geological thing, or even biological. Maybe this is nanotech. By which I mean the manufacture of materials and structures with dimension less than a billionth of a meter. Molecular machines—”

That started an argument.