‘Horrific,’ Charlie said, curious but also a little scared. ‘Have you ever had any kind of …’

Mango shook her head. ‘I use the latest equipment and do all my work twice over. If two altered DNA samples aren’t a perfect match, I start the entire job from scratch. Even the latest Gen-9 equipment doesn’t eliminate minor errors when you splice DNA, but the chances of the same error occurring in two consecutive samples are thousands to one.

‘But if you send your DNA off to some dark lab in China, pay with Bitcoin and get your gene-therapy drugs back in a padded envelope three weeks later, how can you be sure they’ve done the work properly?’

‘I can’t believe people would take that risk with their bodies,’ Charlie said. ‘What about the moral side? Like, it’s basically cheating if an athlete has their genes enhanced? Or cultures where everyone wants male babies, and you end up with an entire generation of horny single men?’

Mango laughed. ‘I like the way you phrase that! I’ll do anything a client reasonably asks, except for z-mods,’ Mango said.

‘I’ve not heard of those,’ Charlie admitted.

‘Z-mods will be huge,’ Mango predicted. ‘They’re a range of gene therapies originally developed to alter brain chemistry in bipolar and severely depressed patients. However, they effectively make a person permanently high. The Z stands for zombie, because that’s what you turn into if you’re always happy.’

‘I’m so out of touch after being locked up,’ Charlie admitted. ‘You can only use the web in the White Boulder library, and only for life skills or a specific school project. And because I was in for bomb-making they let me do college-level math and language courses, but the warden banned me from advanced chemistry or biology.’

‘The genetic patterns for z-mods were only leaked on the dark net six weeks ago,’ Mango explained. ‘They were designed to help people who are institutionalised by mental illness, but I suspect a lot of people will pay a few thousand bucks to live in a permanent state of bliss.’

‘So why are you trusting me with all this?’ Charlie asked.

‘You drifted on to my radar, but I’ve been seeking someone like you for months,’ Mango said. ‘Gene modding work requires precision and intelligence. Pregnancy messes with your body and your brain. Right now, I’m a swollen mess, who gets hot flushes, leaves instant noodles to go cold in the microwave and forgets where she parked her car. And when that’s over I’ll have two tiny humans that will wreck my sleep patterns for years. So, Mango needs a lab assistant who learns fast.’

Charlie felt wary. She’d always loved anything to do with science, and gene editing was the most dangerous and exciting stuff out there. But she’d face years in White Boulder if she was caught.