‘If this sabotage is to take place on a specific day, dependent on wind direction, it is unlikely that reactors that have to be shut down for refuelling would be chosen, so that eliminates six, including Sizewell and Huntspill Head. We know that they are going to wait for a westerly wind, so power stations on the east coast can be eliminated, as a westerly would blow the radioactivity straight out to sea. That still leaves us with eleven power stations, that have between them twenty-eight reactors. And remember also, it is not just the sabotage of British reactors that could contaminate the south of England. There is Monts D’Arrée, in Brittany, Flamanville, in Normandy: both could contaminate the south-east of England if a southwesterly were blowing when they were hit. Similarly, there is the reactor at Bilbao which could contaminate the whole south of England.’

‘What about contamination from American reactors reaching Britain?’ I asked.

‘It would be pretty diluted by the time it got here, but if there was enough of it, it certainly wouldn’t be healthy to breathe it.’

‘But healthier than jumping into mill ponds?’

He looked at me, and I could have sworn he was beaming lethal doses of radiation at me from his eyes. I turned to Fifeshire. ‘Are you going to warn the other countries involved?’

‘No,’ he said, ‘I am not. I’m not telling anyone, not anyone in this country nor anyone abroad, not the Prime Minister of this country, nor the President of the United States, nor anyone else. I think that our only chance lies in secrecy. You’ve established that those operating in this country don’t know what Ahmed told you, and suspect it wasn’t very much. The only other person who could have talked is stretched out on a mortician’s slab in Windhoek.

‘If I tell anyone in any other country, I might as well send a memo straight to Russia, that’s how watertight their security services are. The same applies, quite frankly, to the PM here, and just about everyone else. I am not going to tell anyone at all until either I can tell them who to arrest and where to arrest them, or until I feel there is nothing more we can do. Right now, we, or rather you, Flynn, can do one hell of a lot. As they say in the RAF, right now, we have the height of them, and the sun behind us.’

I nodded. The chief of MI5 was being uncommonly lyrical. When he was lyrical, it meant he was enthusiastic, and when he was enthusiastic, it was usually bad news for me. I wasn’t wrong.

Fifeshire turned to Quoit. ‘If you are right about the fuel, Isaac, and what you have said certainly sounds plausible, then our friend Deke Sleder fits into this little circle very neatly, wouldn’t you agree?’