“Eating?” She laughed, a little nervously. “You make it sound alive.”

“I don’t know what the hell I mean.”

“Do you think we should tell somebody about this?” she asked.

“Like who?”

She shrugged. “The police.”

He blinked. That hadn’t occurred to him, that aspect of the situation. The threat. Maybe Geena was right that he had a one-dimensional mind.

“You know, I don’t like the inexplicable.”

“Oh, come on,” she said. “Be honest with yourself. I know you people. You have a puzzle, and that makes you happy. Something you have to figure out.”

He straightened up. “Buy me lunch and we’ll discuss it.”

She smiled.

“Listen, you want to see 86047 before you go? The bedrock sample. It’s in the case over there by the wall.”

She shrugged. “You’ve seen one Moon rock, you’ve seen them all.”

They made their way to the door, and squeezed into the improvised airlock together.

Behind them, in the central glove box, sample 86047 sat in the lab’s fluorescent light.

It had already been sliced in half and thin samples taken, by Houston technicians and Mike’s careful hands. In the harsh illumination it would have been difficult to tell for sure, but perhaps a careful observer might have noticed something odd about its flat, new surfaces, exposed for the first time since the formation of the rock, billions of years before.

The surfaces were glowing, softly silver.

And, with a rustle rendered inaudible by the layers of glass encasing the rock, a rain of fragments was whispering down from the exposed face.

Jane drove Henry to a multistorey car park close to Waverley Station, and they walked along Princes Street.

You could still make out the deliberate design of the old streets here, Henry thought: a neat rectangular grid pattern, almost like a US city. But whatever character the street had once had was pretty much obscured by the encrustation of plastic and glass of the modern department stores and fast food outlets. There was even a McDonald’s and a Dunkin” Donuts.

“This is what we call the New Town,” Jane said.

“I know. 1760. You told me.”

“The Old Town is the medieval town that grew up around Castle Rock. Narrow, windy streets, coming down the glacial tail there…”

“You’ve been building this city for a thousand years, on top of an extinct volcano. I think you people are seriously crazy.”

“Well, maybe. In the Old Town they burned witches; in the New Town they bred lawyers and scientists.”

“Split personality.”

“Yeah. Jekyll and Hyde.”

“Right. Didn’t Stevenson come from Edinburgh?”

“Yes. Maybe we do have a split personality,” she said. “It was in Edinburgh that the crucial moments in the Act of Union were played out. Union with England.”

“Let me guess. Back in 1672.”