‘Well, I think she has to manipulate her environment just to move through it,’ he said. ‘Who knows what by-products are released? Heat creates thunderstorms, and the temperature at her core will be phenomenal, like lightning. She can’t help most of it. Often, she’s just overexcited.’

‘Where did she come from?’ I asked.

He looked at me without replying. I got the feeling I was doing a test. There were no questions in it, so not sure how I was going to pass or fail, but he was definitely working me out.

‘Let me show you something of what I’m trying to do, Alfie – come through to the workroom.’

Mr Clemm glided out of the kitchen – a floating walk, as if bits of him might come loose – and I followed him through a hallway where his coats hung, huge and long, like people waiting in the gloom.

The next room was full of tools and machinery. Papers and magazines spilt everywhere. Nothing looked new. Nothing was neat. By the door, it smelt like the inside of Mum’s medicine drawer. Further in, the smell changed to oil and sawdust and old paint in metal tins. And Mr Clemm changed too. He seemed easier, more relaxed in here.

Mr Clemm sat down and rested his elbows on the bench, rubbed his chin, and gave me a long considering look. Then he said, ‘She came down in a storm two years ago.’ Even folded up, his arms looked gigantic. ‘And it took me a long time to understand what happened in that storm. She came down in a big flare-up from the sun – a coronal mass ejection, they call them. There was a power cut all over the country, and the aurora borealis – the northern lights – could be seen in Folding Ford, which is almost unheard of. Curtains of light. Beautiful colours.’

Mr Clemm looked so different now. His face was lit up and he was actually smiling. He could never look normal, but suddenly, I got it: he looked happier. Maybe he was glad to be talking about Whizzy. Perhaps he was tired of keeping her a secret.

From the kitchen, Lysander did a quick, short squawk, and I saw that Mum and Lily had followed him back inside. Apart from raising his eyebrows, Mr Clemm ignored it. I had no idea what a coronal mass ejection even was, but he explained it really well. So it’s what happens when the sun’s magnetism gets in a knot and snaps like an elastic band.

Lily thinks I didn’t see her listening in, but I did. She’s always clever about this. She gets an expression on her face that would make Mum think she was totally present and listening to her, but she wouldn’t be; her attention would be somewhere else. Lily can listen to two conversations at once.