Einstein waved a hand in the air. ‘We’ve made some progress,’ he said. ‘We’re struggling, though, basically. In the end I probably know more about it than anyone else in London, but it wouldn’t exactly fill a book. A small pamphlet maybe. Is that what you wanted to ask about? The disease?’

‘In a way, yes. Well, actually, no … yes.’

‘All right,’ said Einstein. ‘I’ll tell you what I know, and I’ll keep it simple.’

He quickly ran through the discoveries he’d made in the labs and what they might mean. Although he stressed that a lot of his ideas were just that – ideas, theories, guesswork. He was more than happy to share it all with Ollie, though, who asked the odd question here and there for clarity. Einstein obviously loved showing off his knowledge and Ollie needed to get to the root of what was bothering him. In the end, as Einstein didn’t look like he was going to cover this area, Ollie came right out and asked him. Although he made sure that nobody else was listening first.

‘What happens,’ he asked, fumbling for the right words, ‘when you, if you, you know, if someone got older?’

Einstein laughed through his nose. ‘There’s no “if” about it really, is there, Ollie? We all get older. Fact of life. Fact of death. No way round it.’

‘Yeah, that’s not what I meant, though. I meant – what happens when someone hits fifteen?’

‘Ah, I get where you’re coming from, ginger. The penny drops with a mighty clang. You want to know if you’re going to get sick.’

‘Not exactly, no, I don’t mean me, I mean just in general.’

‘No, of course you don’t mean you. How ridiculous of me to think that. You were asking about a distant relative or a family friend no doubt. Maybe a favourite pet.’

‘Seriously, I don’t mean me. I just wanted to know. Out of interest.’

‘I’m fifteen,’ said Einstein. ‘Does that answer your question?’

‘Not really.’

‘Not really.’

‘Well … I don’t know what you were like before, do I? So I can’t tell if you’ve changed. I mean, were you always a sarcastic pain in the arse?’

‘Oh, that wounds.’

‘I mean, maybe your rude manner is simply a result of getting sick?’

‘Afraid not,’ said Einstein. ‘I’ve always rubbed people up the wrong way. They can’t cope with my superior intelligence. I’ve always had a very high IQ. I’ve always been very advanced for my age, and I’ve always been unnecessarily rude.’

‘So what you’re saying …’

‘What I’m saying is that it’s not like you’ll get to fifteen and suddenly start frothing at the mouth and trying to eat people.’

‘I won’t – I wouldn’t – get sick straight away?’