The name jarred, but her phone was old and she guessed it was an ancient message triggered by a bug when it switched back on. She was more concerned with where to drive. Mango had kept a radio on while they’d worked and the state of Nevada’s full quarantine had been announced at midnight.

Under quarantine rules, people could make a single final destination journey for a further twelve hours, but were warned that licence-plate recognition systems would catch and fine drivers making multiple journeys.

Charlie opened up her navigation screen. She wanted to give Ed a dose of vaccine, but no matter how hard Charlie looked there was no getting around the fact that Care4Kids was eight miles north, while the Rahimi residence was a little under two miles east.

Working on the assumption that licence plate and speed radar were concentrated on major roads, Charlie plotted a route that avoided freeways and ran through a grid of residential streets. Once she’d drawn the route on her nav screen, and the car had told her that based on current traffic patterns a faster route was available, Charlie decided to check if there were any new messages on her phone before setting off.

She listened to a message from Navid, who guilted her by stating that he was concerned she’d gone out without saying where, and that he trusted her, but it was now midnight and everyone including the boys were worried.

‘Harry Smirnov called yesterday at 1637. Call back or play message?’

Charlie pressed the button to play back as Juno drove past in a big Ford truck, giving a goodbye wave. Harry sounded older, but his voice still evoked the years in White Boulder, when his calls and letters kept her sane, and a flicker of the rejection she’d felt when he’d ignored her messages and stopped visiting a few weeks after she’d been released.

‘Charlie, long time no speak,’ Harry said, with an irritating casualness. ‘I’d like you to call me back ASAP. Vegas Local has received an FBI witness statement. Helen Back turned snitch to get out of some tax beef. She claims that Mango and Veryan Kowalski-Clark run a gene lab. Your name crops up too, saying that you’re their best lab rat. Even if that’s not true, you’re gonna have the Feds on your case. Call me back when you can. It’s Harry … Harry Smirnov, obviously.’

Charlie felt a stab down one side as she breathed. She thought about calling Harry straight back, or talking to Mango. Mango might still be tidying up in the RV if she ran, but Charlie decided her priority was to give Ed his vaccine, then head home for a tricky conversation with her foster parents.