Tom gives me a sceptical look. ‘Have you driven one before?’

‘No, but it can’t be that hard.’

I arrange our bags in the trailer and he climbs inside. Once I’m sure he’s comfortable, I straddle the bike and start the engine.

‘You OK?’ I call, glancing back.

He doesn’t answer, his attention taken by his phone, and I almost don’t dare to hope.

‘Do you have network coverage?’

His stricken face tells me the answer.

David warned us there was no mobile signal and no way to contact the outside world if we got into trouble. He’s the only person who knows we’re here, and our only way of returning to the mainland. My heart sinks, but then I remember the confused look on his face when he realised his head was bleeding. If he’s anything like anorak man, he won’t remember what happened and will return to the island as planned.

I try to sound positive. ‘He said he was coming again in a week.’

Tom’s jaw tightens. ‘And if the same thing happens?’

I twist back around in my seat, unable to answer.

The truth is that I don’t know anything. I don’t know why a group of witches from another world would want to hurt me, or why the shadows didn’t possess the boatman on the crossing over. My mum said that with some people it can take longer for them to get inside, but they always find a way. Maybe it will be her attacking me next time, or Tom.

I squeeze the throttle and the bike gives a throaty roar and then dies. I start it again and it lurches into life. Concentrating hard, I ease the throttle and do my best to keep it steady as I take us onto the track. The trailer rattles along behind me and Tom curses when we hit a bump. I can’t blame him for being angry. If I hadn’t talked him into coming, he’d be on the mainland now. Instead he’s here with me – stuck in a nightmare.

We pass through the village and then I turn and take us down through the fields, gripping the handlebars so tight my palms hurt. A splatter of rain hits me and I glance at the darkening sky and realise the fog is lifting. Seeing the lighthouse fills me with foreboding. I should have begged my mum to leave with me, but what good would it have done? The shadow would still have possessed the boatman; we’d still be stuck here.