I’d detested Dorothy because she’d assumed power purely because of her age, but I began to respect her when I saw that she was the first to think about vital matters. Each time the women embarked on a discussion and then lost track, Dorothy would tactfully interrupt them and make a useful suggestion. I saw that her authority came from her wisdom, but I wasn’t inclined to wait for orders from her. I preferred to do as she did and think ahead. After a few days, we realised that we had used up half our provisions.

‘We must go back and get some more food,’ she said, ‘and make a list of what is down there. After that, we will decide whether to stay here or leave.’

In her mind, that ‘we’ still only meant Anthea and her, but I knew it would soon include me.

About fifteen of the women came with Anthea and me. They weren’t going to go down into the bunker, but would help carry everything we brought up. It was also suggested they should keep a lookout, which I thought was pointless. I said so to Anthea.

‘You may be right,’ she replied. ‘But I’ll feel happier too if there’s someone keeping watch at the top. You never know. We don’t have a clue as to why they left, or how, so we can’t be certain they won’t come back.’

That made sense. It is impossible to predict what might happen in a world where you don’t know the rules.

So we retraced our steps back to the cabin and, as we drew closer, we fell silent. I’d never been very talkative, but I was used to living amid a steady drone of chatter, and now all that could be heard was the crunching of the stones beneath our feet.

‘If we’re going to walk, we’ll need better shoes,’ observed Anthea. ‘These sandals won’t last two days.’

In our haste to leave, no one had paid attention to the rooms we’d rushed through, but I thought I recalled seeing boots rather like the ones the guards wore.

‘The thing is there are forty of us!’ exclaimed Greta. ‘When you go barefoot, the soles of your feet harden, so perhaps we should …’

But she didn’t finish her sentence and nobody started on the usual speculation. We were getting nearer, and a certain foreboding made us silent. We unwittingly slowed our pace.

‘Nothing’s changed,’ said Annabel, as we reached the cabin.

There was a light wind. If we stopped talking and kept still, it whispered the same song in our ears. That day, the clouds were back, the sky was high and white. I saw that my companions were shivering.

‘Let’s go,’ I urged.

We’d been in the open air, and I recoiled in disgust: when we were two-thirds of the way down, the smell hit me. Anthea explained:

‘That’s our own smell that has lingered. You’ve already forgotten it. The ventilation system provides air that is breathable, but that’s about all.’