Judah didn’t seem too worried, but the grandmother looked flustered. ‘Can we consider something else for his memory? So many other boys in his school have memory mods. It’s hard to compete academically.’

‘I did some research,’ Charlie said. ‘There are other modifications that improve memory, but none that I’d be happy to use until we have a better idea of the long-term effects. Judah is still having mods that will improve cognition and IQ.’

Judah sat forward. ‘But all the physical stuff is OK, right?’

Charlie smiled. ‘Absolutely. The mods will darken your skin, as if you have a good tan. Straighten that tangled hair. Improve muscle mass and bone density, and probably increase your eventual adult height by three to four inches. The mods will also give your immune system a boost, protect against depression and reduce your chances of many cancers and long-term obesity.’

‘You modded two boys in my class,’ Judah said excitedly. ‘They’re so ripped now. They can crush me!’

‘That’s David and Ben, isn’t it?’ Charlie asked, and Judah nodded. ‘I’m glad they’re doing well.’

‘I have to say this makes me queasy,’ the grandmother interrupted. ‘But what can I do? He’s surrounded by boys who are modded. They’re faster and stronger. They do better than him academically and he comes home upset. Once a couple of boys get enhanced, they all want it.’

Charlie had no medical qualifications, but over time she’d realised that people liked her to act like a doctor and give words of comfort, even if she was only parroting information that could be found online.

‘I think we all stress over modding teenagers,’ Charlie reassured her. ‘But the technology is far better than it was even a couple of years ago. Instead of injecting stem cells until modded cells outnumber the regular ones and start to take over, we can now actively destroy the original cells too.

‘The transformation from your original genes to enhanced ones is faster and, whereas everyone used to take auto-immune drugs and three-quarters of people had some kind of unpleasant reaction to gene therapy, the immune drugs are now built into the treatment and less than five per cent get anything more than a slightly raised temperature. It’s a lot more work for me – which is why other labs still use less sophisticated methods – but it’s worth the effort.’

The grandmother managed a nod and a slight smile.

‘If you’re both happy, I’m ready to show Judah how to handle his injections. But I will need to take payment before beginning the treatment.’

‘Can you run through fines and registration again?’ the grandmother asked.