‘I like it up here,’ said Skinner after a while. ‘I come up here all the time. Day and night. For me this is the whole world. Our parents never let us go out when we were growing up. Never in public. When the disease struck they brought us in here. This is all I’ve ever seen, the view from up here. I wonder all the time what it’s like, the rest of the world.’

‘It’s pretty crap at the moment, to be honest with you,’ said Blue.

‘I want to see it, though.’

The cat shifted inside Skinner’s jacket and Skinner soothed her. ‘She doesn’t like it out here.’

‘Can’t say as I’m enjoying it much either,’ said Blue as the wind switched direction and directed a spray of rain down his neck. ‘Come on. Let’s go down. I’ve seen enough.’

As Blue went to move off, though, Skinner held him back with a hand on his sleeve.

‘There might be a cure,’ he said. ‘There might be stuff here you could use. But we wouldn’t know where to start. We’re not scientists. Our parents were either scientists or doctors, but we were too young to learn anything and they all died before they could work anything out; they were trying, they were trying real hard. They felt guilty, you see.’

‘Of spreading the disease, of bringing it here to England?’

‘That would have happened anyway. As soon as the Inmathger came out of the forest and met other humans.’

‘What then?’

‘The thing is,’ said Skinner, ‘it was clear even before we were born that there was something wrong. That we weren’t growing normally. But, like I said, they kept it secret, covered it up. They hid us away from the other people they worked with. Didn’t tell anyone. All of them who had children. And when we were born we never mixed with other kids. Nobody knew about us at all.’

‘But why?’

‘Have you ever heard of toxoplasmosis?’

‘What’s that?’

Skinner tickled his cat under the chin and lifted its head slightly.

‘You can tell us all about it, can’t you, kitty?’ he said.

‘Inside,’ said Blue. They called over to Achilleus and headed for the door. Once they were safely back in the dry Skinner fastened the door shut and, as they walked along the metal walkway high above the warehouse floor, he explained.

‘Toxoplasmosis,’ he said, ‘is a parasitic disease that used to kill thousands of people every year, and its main host is cats.’

‘Never knew that,’ said Blue. ‘I ain’t going nowhere near Mister Tiddles there.’

‘It’s Mrs actually,’ said Skinner. ‘Mrs Jones. But chances are you already have it.’

‘What? Toxic Plodmosis?’