‘Because, Professor Wilde, it’s going to bring about the collapse of civilisation. There are now nearly eight billion people on the planet. Eight billion. Twenty-five years from now, by 2050, it will be ten billion. They’ll all need food. They’ll all need water. And houses, and medicine, and fuel, and a hundred and one other things. Competition for resources will change to fighting for them – first on a local scale, then nationally, then internationally. I guarantee you that within ten years, we’ll see a full-scale war over control of water supplies. Probably between Egypt and Sudan or Ethiopia for the Nile, but it could be anywhere. Wars mean refugees, who add pressure in other countries, and the whole thing spins out of control.’

‘You’ve been reading your Thomas Malthus,’ said Nina. ‘I know the theory: population growth leads to catastrophic collapse as demand for food outstrips supply. But it didn’t happen in the nineteenth century, or the twentieth, because we came up with more efficient ways of producing food. Why would it be different now?’

Eleanor was clearly not used to being challenged on her assertions, nor did she welcome it. ‘I know what I’m talking about! I’ve spent the last twenty years of my life researching it. It will happen! Why do you think I moved to New Zealand?’

‘For the bungee jumping?’

An angry laugh. ‘I’m not the only wealthy person – or smart person – to move here. Civilisation as we know it is unsustainable. The crash is coming, believe me. The rest of the world will tear itself apart as everybody fights over the remaining resources, and billions of people will die.’

‘But not you? You’ve built yourself this nice little bolthole and are going to hide out while the world burns?’

‘I have a more worthy goal, but yes. This is the ideal place. Isolated, but with resources – water, geothermal power, farmable land. I’ll be able to wait out the crash in safety.’

Nina couldn’t help noticing that she was speaking in the singular – and her son was aware of it too. However, there was another point she had to make. ‘Forgive me for pointing out the obvious, but I don’t think you’ll be around long enough to do that, however many Miller & Family vitamin pills you take. You’re in your eighties, I’d guess? And you don’t look in good shape. Another five years will be pushing it, never mind ten or twenty.’

‘Hey!’ cried Miller, outraged. ‘You shut up.’

‘She’s right,’ Eleanor told him. ‘Left to my body’s own devices, I’d be lucky to last another ten years, even being optimistic. But that’s where you come in.’