For it was clear that the sudden, unexpected rash of minor volcanism in the Canyon, like that in a dozen other sites around the world, was directly related to the particle cloud that had spread around the planet from Edinburgh: what Henry Meacher called the Moonseed, the alien infection that — for weeks, it seemed — had been raining down out of the stratosphere and was eating into the very rock beneath her feet.

The precedent of Edinburgh for what would follow was not encouraging. And what she needed to find out was what would happen when the Moonseed got into those deep old rocks.

On the way here, she’d had another e-mail, from Alfred Synge.

› Here’s what we think is happening in Venus. And I’m sure you can express it, not to mention understand it, far better than I can. › Take one of your rolled-up ten-dimensional string objects. Pinch it, like compressing a garden hose. As you approach zero width, you generate quantum-mechanical waves, membranes wrapped around the scrunched dimensions. The waves are extremal black holes…

Actually Monica didn’t agree with the nomenclature here. These “black holes” were nothing like the collapsed stars of astrophysics. They were just solitons, clumps of string fields; the physicists preferred to call them black bubbles or black sheets.

But arguments about nomenclature weren’t the most important thing right now, she reflected.

› The black holes are massless, so they flee at the speed of light. But, like massless photons, they aren’t without momentum. So they exert a push. › Monica, we think that inside Venus there’s an organization of mass and energy that is working as a generator of extremal black holes. Maybe that’s what the transformation of the planet is “for’, if you can think of such events as having anything like a single purpose. There is a fountain of black holes streaming from where Venus’s north pole used to be. And it is pushing what’s left of the planet out of its orbit, away from the plane of the ecliptic. It’s like a rocket, Monica, a black hole rocket…

It was fanciful, abstract. The whole Venus event had become a kind of theoretical toy to be kicked around by the young and/or over-enthusiastic, including Alfred, and the hypotheses just got wilder. It was impossible to connect to the grubby reality of a cracked cinder cone, here in this great chasm.

And yet, it seemed, connected they were.

Alfred’s mail ended in rambling, a rant about NASA’s post-Edinburgh decision to destroy its remaining forty-billion-dollar Moonrock stock. The genie is out of the bottle! The horse has bolted! This is vandalism.

No, she thought. You don’t understand. It’s a symbol. Appeasing the gods.

“Tell me about the Inner Gorge rocks,” she said to Scott Coplon.