‘I mean…’ Marie hesitated. Indecipherable emotions slid across her face – she had always been so hard to read – before she masked them with a half-hearted attempt at a smile. Forever the fearless one. Always trying to make her twin feel better. ‘We have to be good. Brave. We’re together, that’s the main thing.’

‘Might they split us up? Who are they? Don’t let them take me away.’

‘I won’t,’ Marie said firmly. ‘Cross my heart.’ But Leah still looked terrified until Marie curved her little finger into a hood and offered it to her twin.

‘A pinkie promise can’t be broke

Or you’ll disappear in a puff of smoke

This is my vow to you,

I’ll keep my promise through and through.’

‘See, it’ll be fine!’ Carly took a deep breath to steady her voice. ‘Marie’s right.’ She glanced at Marie. ‘We’ll treat it like a game. A mystery. We’re good at solving those, aren’t we?’ It wasn’t too long ago they’d created invisible ink. If only lemon juice could help them now. ‘Let’s make a plan.’ She crunched over the broken glass and perched on the mattress. It was filthy but safer than the floor. She patted the space either side of her. The twins huddled against her. ‘Right. I don’t know who took us, or why, but there’s two of them. Doc—’

‘A doctor?’ Leah asked.

‘No, but I call him that because of his boots, and Moustache is the other one. They haven’t hurt us yet so I don’t think they will.’ Carly crossed her fingers behind her back.

‘Look.’ Leah pointed with a shaky finger. On the wall, in jet black aerosol, the words, You’re going to die.

‘That isn’t aimed at us,’ Carly said. ‘Look how many other things have been written.’

‘Run.’ Leah read another.

‘I meant names and stuff. It’s vandals. Some of the kids at school have been here. Nobody is going to die.’

Think.

They fell silent.

Think.

Suddenly it came to her.

A plan.

‘Marie, we need you to pretend to be ill.’

‘Why?’ asked Marie.

‘Because you’re the best at acting.’ Marie had a confidence Carly could only wish for. Last Christmas she’d played Annie. Mum had styled her red hair into a mass of ringlets and she’d stood centre stage, belting out ‘Tomorrow’ without a hint of self-consciousness.

‘I know I’m the best. Acting is easy. You just pretend. I meant why should I look ill?’

‘That way I can call the men and they’ll think you’re really sick. If they’re worried you might die they’ll have to take you to hospital. There’ll be police there.’ Carly thought but she didn’t know. There were always policeman chatting up the nurses on Casualty.

‘No,’ said Marie. ‘It’s better we stay together. Besides, they won’t hurt us.’ She tried to form it as a statement. Carly knew she was trying to reassure Leah but there was still a tinge of doubt to her voice. This was the first time in her eight years Marie had caught a glimpse of how harsh the world could be and Carly didn’t blame her for not wanting to accept it. ‘They didn’t mean to scare us, did they, Carly?’ Marie raised her eyebrows and tilted her head towards her twin.