“Go ahead, Dr Meacher.” Her accent was crisp and precise; she was cheery, dapper, competent, very Scottish. “I’ve seen you on the TV.” That was likely; he’d featured, to his chagrin, as a strange-but-true item on the local news, the eccentric Yank here to study the Moon rock. “Besides,” she said, “I can see the hammer on your belt. Just don’t fall in.”

“I won’t.”

“There are Government scientists coming up to study this. It’s caused quite a stir.”

“I’ll bet it has.”

She nodded. “We’re going to need more cordon tape, aren’t we?”

“That you are. Take care, officer—”

“Constable Decker.”

He left her at her post.

He set himself to walk around the perimeter of the primary pool at the summit — as close as he could get, given the police tape — counting his paces as he went.

The pool lay over the craggy agglomerate like a silvery blanket, dimly reflecting the afternoon sun, like a splash of mercury paint. In some places it had actually adjusted the shape of the Seat; bits of the old plug had subsided into the spreading silvery pool, as if dissolved in some powerful acid.

He approached his starting point once more.

There was Constable Decker, standing relaxed, and a little further down the hillside there was the patient group of cultists. Just like every day, they seemed happy; he could hear guitars, folk songs, raucous laughter. A TV crew was making some kind of report, a girl reporter being filmed against the glimmering background of the Seat’s wound The reporter was in a radiation-proofed smock, but most of the other people here weren’t.

The whole incident was turning into a kind of low-grade circus, he thought, an item for the end of the TV news, a little scary but too strange to take seriously, like skateboarding dogs and skydiving wedding parties and Moonstruck Yank geologists.

Henry had a palm-top computer in his jacket pocket; he pulled it out. He entered the paces he’d counted, made an adjustment for the fact that he hadn’t been able to approach the rim of the pool as closely as before because of the tape, divided by pi on the assumption that the pool was circular… He entered the new data point onto a log-log graph he’d set up in the palm-top. The graph reduced the growth pattern to a straight line.

The new point was close to the line he’d established with his earlier data.

The growth he saw today was just what he’d found before. Steady. Relentless.

“I was right about the damn police tape,” he muttered.