The desk officer stopped him, of course, and Henry resorted to a mix of persuasion, string-pulling, ranting and bluster to penetrate the layers of bureaucracy which, inevitably, surrounded the decision makers here. He even produced his passport. But ultimately it was his physical state, the filth and blood, that bore testimony that here was a man who had just walked out of the heart of it all, that lent him the authority to bamboozle these low-ranking cops.

Actually it wasn’t the first time he had had to bully his way through obstructive organizations: a career at NASA had trained him in that.

Even so, he was kept waiting on a hard-backed plastic chair, cradling a polystyrene cup of what might have been tea, for more than an hour. Then, at last, he was ushered into the big incident room that was, he was told, serving as the command centre for the response to the emergency.

The control room was chaos, on first appearance.

Police officers and civilians moved from area to area, desk to desk, shouting and gesturing. Mobile phones and pagers sounded continually. The walls were coated with white boards, on which were listed cryptic notes, contact numbers, lists of areas and actions. There was an immense map of the east of the city, cluttered with colour-coded stickers: bright primary colours, red and green and yellow and blue. There were yellow emergency jackets and hard hats, some scorched, hanging on pegs and draped over the chairs. The desks were covered with yellowed Home Office procedure manuals.

On one desk he saw a document marked “Evacuation Plans 2 and 3’. It was dated 1938 It was the plan for evacuating the city that had been used during the Second World War.

Holy shit, he thought.

At last he was brought to the Chief Constable.

“Yes. I’m Romano. Who the hell are you?”

The Chief Constable was a woman, fifty-ish, with strong Italian-extract features, hair that was thick and black though streaked with grey. She stood before the big area map, hands empty, an island of stillness amid the bustle of the pot-bellied male cops around her.

“Henry Meacher. I’m from NASA.”

Romano laughed. “NASA. That’s all we bloody need.”

“Yes, you do,” Henry said seriously. “Are you the decision maker here?”

“For now.”

“Then I need to understand what you’re planning.”

Romano eyed him. Henry thought he could read the calculation there, the mind of a senior officer accustomed to using her time efficiently. This guy is different. He might have something. Or he might not. He has thirty seconds before I throw him out.

Romano said, “We’re evacuating the area in the vicinity of the disaster.” On the wall map a rough chinagraph-pencil circle, diverting to follow the lines of the streets, enclosed Arthur’s Seat and the Moonseed surge area, to a radius of about a mile. “We’re setting up assembly points and Rest Centres here and here.” Points on the roads leading out of the marked area, and outside. She raised an eyebrow at Henry. “Does that meet with NASA’s approval?”