Izzy had never had a boyfriend. We’d talked about boys, and plenty of them had asked her out over the years, but she’d always said no. She told me that her standards were too high, and I knew that my dramas had distracted me from asking more.

She was so happy that I wanted to bottle it and make it into a perfume, to be used any time you needed to have a brilliant day. There was something else too, though. Underneath it all she was nervous.

‘OK,’ she said. ‘You ready for this?’

For a wild moment I thought that she, too, might have fallen for a ghost.

‘Yep! Tell me!’

‘It’s someone I met online. We chatted for ages and I’ve met them in real life now too and I’m really happy. I’m so happy, Ariel. I know it’s really early days and I’m trying so, so hard to play it cool, but I’ve never felt like this. Finally …’

‘Finally you’ve met someone who meets your high standards?’

‘Exactly. Finally I have.’

I began to realize.

‘Why are you saying they?’ I said.

She shrugged. ‘Because I was a little bit too shy to say she,’ she said through a mouthful of Twix. She looked away and then her eyes darted back to me. I hugged her.

Izzy’s new love interest was called Tally, and we talked about her for ages. She was seventeen and had lovely thick black hair. They’d met online and clicked straight away. While I’d been looking after Zara and Coco they’d been on their first date. They went for tea and cake and then a movie, and Izzy was buzzing and wild with joy.

‘It’s not just her,’ she said as the train left Devon. ‘Although it is her. It’s very much her. And it’s everything. It’s having the confidence to be myself at last. I tried so hard to like boys because I thought it would be easier, you know?’

I realized that I wasn’t surprised, that it made perfect sense. I was so happy for her.

I was also a bit sad for myself. I hadn’t had any of this, with Joe, and I never would. I couldn’t psyche myself up to tell anyone about him because he’d been dead for twenty years. No one would ever be pleased to hear about this relationship. It could never make sense to anyone but us.

And I didn’t want anyone else. I could have rekindled things with Jack, but I loved Joe. Only Joe. It could only ever be Joe.

We were supposed to be revising the Power and Conflict poems for English lit, but we didn’t even take a book out of a bag. We ate all our food and talked about Izzy and Tally, and then we talked about our mission in London.