She hardly remembered being captured. Although that’s not what the Windsor kids called it. They said they’d rescued her. Saved her from a mob of grown-ups. Said she could have died.

Ella sometimes wished she had died.

It had all been her fault. What had happened to Malik. All her fault. He’d risked everything to take her to safety. She couldn’t go anywhere without bad things happening. Maeve and Robbie and Monkey-Boy. All her fault. In her worst moments she imagined she was to blame for everything – the disease, the grown-ups, her parents dying, Sam being taken, Maeve and Robbie and Monkey-Boy …

Round and round in her head it all went until she was too tired to care any more. It was like she’d been at the bottom of a deep black hole and had climbed out and found herself in a world without colour. Nothing mattered to her. She couldn’t connect; stuff just went on around her. She was numb. Couldn’t feel anything.

In different times Ella would have been very happy at Windsor Castle. It had reminded her of Buckingham Palace. Not surprising really, as it had been one of the Queen’s homes. Only this one was a proper castle like out of a fairy tale. A castle full of children.

There was even a prince and princess there, the Golden Twins: Golden Boy and Golden Girl. She’d met them early on and they’d been nice to her. Nice but not really that interested. She was just a little girl who’d got caught in their nets, a shrimp, a sardine. She’d tried to tell them about Malik, but they wouldn’t listen.

Most of the kids at Windsor had been kind to her. They’d looked after her and fed her and given her pills for her headaches. And she’d made a friend, a girl who seemed to be in charge of everything inside the castle, organizing the medicine as well as the food and the armour and the weapons and the people.

She was a teenager who called herself Go-Girl. At first Ella thought her new friend was called Golden Girl, who she’d heard so much about. Thought that Go-Girl was the queen of the castle, and Go-Girl had pretended to get cross.

‘I’m not Golden Girl,’ she’d said. ‘I’m Go-Girl. Don’t you forget it – Go-Girl! I had the name first; Golden Girl stole the idea off me. I was always called Go-Girl back in London. We had a gang, we were going to form a band, we were like superheroes. Go-Girl was my rock-star name. There was me and The Fox, and Cool-Man and Shadowman and Magic-Man and one more, oh yeah, Big-Man. Mostly all dead now. But they can’t kill Go-Girl!’

She tried to make Ella laugh, to trick her out of her mood. She really tried. But Ella stayed in her mood.