After a delay to the MAC flight from Nevada, Toad didn’t reach Hereford until late that evening. I was having supper when I got a message to say that he was in the SAW. As soon as I’d finished I went over to the wing’s special armoury – and there he stood, dry-washing his hands. After a couple of months in the desert sun, anyone else would have had a really expensive tan, but all he’d managed was to turn a sickly yellow.

‘Hi, Toad,’ I went. ‘You made it. Where are your packages?’

‘Right there.’ He half-turned to his right, pointing behind him, and there, sitting on a wheeled pallet by the wall, were four black steel trunks, each maybe two feet by four feet, and only a foot deep, with a couple of smaller boxes on top of them. The only markings, stencilled in white paint, said ‘A-1, A-2, A-R’ and ‘O-1, O-2, O-R’.

‘Jesus!’ I said. ‘So they come in kit form and have to be fitted together.’

‘Oh yes. Early portable devices were in two parts. Then, as technology improved, they started making one-piece models – real suitcase bombs. Those are still around, but when something more powerful’s wanted they’ve gone back to this modular design.’

I was horribly fascinated by the thought of what the black cases contained and what they could do. But at the same time I couldn’t help being irritated by Toad’s proprietorial air. There was something in his gestures, in his attitude, which said, These are mine, and you can keep your distance.

‘Everything all right?’ I asked.

‘Sure.’ He rubbed his hands some more.

‘Good course?’

He nodded.

‘Have you been briefed about the operation?’

‘Not yet.’

‘Well, we’re leaving for Moscow the day after tomorrow, so there isn’t much time. Better come on up, and I’ll give you the bones of it now. Then maybe you can brief me and Whinger on the devices in the morning.’

We went up to the main briefing room, and I unlocked the safe in which I’d stored the site plans and the CDs. Toad hardly spoke as I went through them, but I knew that his quick mind was soaking in every detail.

‘The Orange site is out in open country,’ I told him. ‘Part scrub-land, part forest. As far as I can see, it’s just going to be a hole in the ground: either one we find and adapt or one we dig ourselves. So I don’t see much of a problem there. The tricky one’s going to be Apple. This access shaft, in the courtyard, is at least twenty feet deep.’

‘Pulleys,’ said Toad.