I grinned at her. ‘Thank you!’

We talked about school and about the differences between her school and mine. Zara’s best part of school was reading and writing, and I told her that I liked that too, but that history was my favourite, and we talked about how nice it was to be allowed to give up subjects you didn’t enjoy and then, before we knew it, we were at their house, and Izzy was leaving for her mysterious appointment. She gave me a look. I gave her one right back.

‘Come in, Izzy!’ shouted Coco. She stamped her foot. ‘Come in!’

‘Literally can’t,’ she said, holding up her hands. ‘Your parents only asked Ariel. I can’t come into your house as a stranger when they don’t know me and you kids are here. Basic safeguarding, Coco. Tell you what, get them to invite me next time and I’ll totally come in then, OK? Also, I have to be somewhere at five so I need to dash.’

She left, half running, and I went into the house and settled down to watch TV with the girls because after a long day of school that was all any of us wanted. I made a jug of squash, thinking of the squash Mum had given Joe today, and handed out biscuits, and found that I quite liked being in charge. I’d always been the youngest and I still often felt as if I was about Zara’s age.

I watched Zara watching telly and laughing, and overlaid her with Joe. I knew that, right now, he was at Beachview on his own and I hoped he was all right, though I knew that, in spite of the joyous pissing around he’d done today, nobody could be less all right than Joe. I sometimes had a bleak vision of him, two hundred years into the future, sitting there every day. Forget the flames: waiting for eternity in a Devon shopping centre, long after everyone you knew was dead, was surely hell.

When the episode finished, we had a game of hide-and-seek, which was raucously entertaining for about half an hour before it ended scarily when we really couldn’t find Coco. For ten horrible minutes I hyperventilated at the idea that I was going to have to tell Joe’s family that another child had gone missing. She turned up, curled in a ball, in a laundry basket under a towel.

‘I won! I won!’ She laughed as she jumped up. ‘You lost and I won!’

I was so relieved I was almost crying.

‘That was next-level hiding, Coco,’ I said. ‘Are you always this good?’

‘It’s easy for her,’ Zara said. ‘She’s small. She can squeeze in anywhere.’

‘Yes, I AM always so good,’ said Coco, and I looked at the clock. It was quarter to six. Joe would be gone now, and, in this world, Gus was about to come home.