‘Well, we can’t get out under the floorboards,’ he said, as if explaining to somebody half-daft. ‘Concrete partition wall. There’s a gap between the ceiling of this room and the floor of the guest bedroom that I can just about wriggle through.’

I looked at him as if he were mad. ‘And why would you go and do that, John Goose?’

He waved at the room in general. Pointed at his injured guts and then at me, all wet and shaking and sore. ‘We’re locked in, Felicity. And the people out there have already hurt you and hurt me and whatever they’re up to, I don’t think they’re going to suddenly wave us goodbye and head for the hills when they’re done. We need to get ourselves far away.’

I shook my head. ‘You’re expecting me to go up there too? I’m fifty-five next birthday! I’ve got gallstones! There could be all sorts up there!’

He took the tail of his cardigan and wiped the sweat from his face. ‘This little thing,’ he said, holding up the black cube. When he spoke it was like he was reciting something he’d learned off by heart. ‘It’s a listening device. You’ve seen them in the films. It switches on when the electrical vibrations nearby undergo a significant alteration. It switches itself off after a certain amount of time without a frequency change. Basically, if you’re in the room above and switch on a lamp or the wireless, it starts transmitting.’

He sounded like he was speaking a foreign language. I started slapping the length of copper pipe against my palm, jittery and frozen through. ‘And how do you know that?’

‘I put it in,’ he said, with a shrug that didn’t suit him. ‘Cordelia – she set it up. I never had to do anything dangerous, I swear. Just once in a while a package would appear in the glove compartment of the car and I’d have to pop along to the house and retrieve one gadget or put another one in. She explained it all. I didn’t give it a second thought. I stopped when …’

I stared through him, unsure why he stopped. He met my gaze, a sheen to his eyes, and I knew what had happened. It was our boy’s death that changed him, and us, and the whole of our world.

I gave a little nod. It wasn’t the hug that some people would have offered, but in the language of our marriage it stood for pretty much the same thing.

‘I’ll give her merry hell for this,’ I muttered, as John started fiddling with the gadget, gripping the pipe between his knees.