Amy didn’t seem to hear. He could see that she was thinking about something again. It was very unnerving the way she did that, switched to auto pilot while her brain concentrated on some totally different subject. Perhaps she was already learning to multi-task, practising that skill all women claimed to have.

‘It’s just like Draco Malfoy, in that shop in Knockturn Alley,’ she said.

Cooper frowned, stumped again by the turn of the conversation. ‘Is it?’

His brain turned over, trying to pin down the reference. It was humiliating to find that his brain worked so much more slowly than Amy’s but he was finding it more and more difficult to keep up with his nieces’ interests these days. Their lives seemed to change so quickly, the pop stars they liked being different from one week to the next. Even the language they used evolved so rapidly that it left him behind.

‘Wait a minute – Draco Malfoy, did you say? That’s Harry Potter.’

‘Of course it’s Harry Potter.’ Amy could barely conceal the contempt in her voice. ‘It’s in The Chamber of Secrets. Draco Malfoy finds a hand of glory when he’s in the shop with his father. “Best friend of thieves and plunderers,” that’s what the shopkeeper says.’

‘“Best friend of thieves and plunderers.” OK, that would make sense.’

‘So it’s magic,’ said Amy.

‘Yes, of course. What did you think it was?’

‘I thought it was for real. Well, it’s in the museum, isn’t it? All this other stuff is for real – the costumes and the tools, and the old furniture.’

‘Yes.’

‘But the hand of glory isn’t real – it’s magic.’

‘It’s a genuine hand,’ said Cooper defensively. ‘A hand that belonged to a real person once.’

‘But it’s still magic. Magic is make-believe. Harry Potter is made up. It’s fiction, Uncle Ben.’

‘The fact is,’ said Cooper, treading cautiously, ‘people in the past believed those things were for real. They didn’t know that magic was just something out of stories like Harry Potter. They actually thought it worked, in real life. The hand of glory, all kinds of stuff.’

They got to the door of the museum and looked out on to the street. There were fewer umbrellas being carried by the pedestrians now, so the rain must be easing.

‘People can be really weird, can’t they?’ said Amy. ‘They believe in such stupid things.’

The old man’s dreams were worse during the day. He drifted in and out of consciousness, hardly aware of his surroundings, pressed down into the darkness of sleep by a great weight. At times, he wasn’t even sure he was still alive, it felt so impossible to wake up. It was so difficult, so far beyond his strength.