Inside the cafe, she leads us to a booth and orders a pot of Earl Grey tea and a toasted cheese-and-tomato sandwich.

Dad orders two plates of scrambled eggs and a glass of orange juice for me. ‘And I’ll have a coffee, please,’ he says. ‘As strong as you can make it.’

As soon as the waiter leaves, Sylvie lays both hands flat on the table in front of her. Her silver rings are studded with chunky blue, green and rusty-red stones. The stones’ odd shapes make me shiver. ‘So. What happened?’ she asks in a firm voice.

Dad takes a breath before answering. ‘Merry was practising a disappearing trick and she hasn’t come back. She said she’d be gone for thirty seconds. And that was about thirty-six hours ago –’

‘And why haven’t you brought her back?’ Sylvie interrupts, and points at me.

‘Me?!’ I say, sitting back in surprise. ‘I have no idea how to!’

‘What’s she taught you so far?’

A familiar frustration swells inside me. ‘Nothing,’ I say quietly.

‘How old are you?’ she demands.

‘Eleven.’

Her eyes widen with disbelief. ‘And she’s taught you nothing at all?’ A flicker of something crosses her face. Is it fear? Anger? Whatever it is, I don’t like it. She looks up at the ceiling and bangs a fist lightly on the tabletop. ‘Oh, you silly, silly girl, Merry,’ she says.

She glances at Dad. ‘I shouldn’t tell you this, because you are a non-magician, but you both deserve to know.’ She pauses. ‘In order to disappear, Merry used one of our most ancient and dangerous spells. Dangerous because it’s to do with other dimensions. You know what I mean by other dimensions?’

I shake my head.

She raises her eyebrows. ‘Well, to put it simply, Merry has taken herself to a parallel universe – another version of her life, which is taking place at the same time as her life in this universe. It’s where people or things go when we disappear them with magic.’

‘What?!’ I say. ‘What do you mean, another version of her life?’ My head is whirling. ‘Where exactly is that? And how do you get her back?’

‘Think of it like this ...’ She picks up the sugar dispenser and tips a thin line of sugar onto the tabletop. ‘Let’s say this is your life, going along, day after day. Then you make a decision or something changes. Say you decide to go to live in Finland or … you have an accident.’