Tom trudges along the foam-covered pebbles towards the boat, and I follow him. Maybe it’s the damp air, but the smell of sulphur is stronger than ever. It must be coming from the seaweed, strewn across the shingle in thick dark ropes. I think about the dead seal pup and wonder if that’s where the rotting smell is coming from. Or maybe it’s the harbour wall itself, which is covered with tiny rough barnacles and furry lime-green lichen that seems to almost glow in the pale mist.

‘Hello, anyone there?’ shouts Tom.

David’s head appears on deck. ‘Hi, come on up!’

Tom waves me over and then climbs the metal ladder. The boat isn’t as big as I thought, so presumably David must do several trips when he takes the sheep across. I can’t see them from here, but I can hear their plaintive bleats and the faint clatter of hooves.

I climb the ladder and Tom hauls me aboard.

‘Missing the open sea, eh?’ laughs David.

Tom’s face pales and I realise why he only ate toast this morning. He forces a smile. ‘Yes, that’s right. I was hoping to go back with you today, if that’s OK.’

The boatman eyes me warily. ‘Decided to leave early, then?’

I shrug. ‘David, I wanted to ask if –’

An alarmed bleat sounds behind him. The noise is followed by another and another, and then there’s a panicked snort and the clatter of hooves.

‘What on earth?’ He strides towards the sheep, but then stops and peers down at his feet. I can’t see what he’s looking at, but something is wrong. A waft of decay reaches my nose and I grab Tom’s arm.

‘We should go.’

‘What? Why?’

A swirl of shadow moves across the deck and grows bigger, rising up to stand in the vague form of a human, its black outline hazy and indistinct. A second later, it slides across David’s face. He stares at me, his eyes bulging, then tilts his head to the side, making the bones in his neck pop and crack. Again and again he repeats the motion, like some kind of automaton.

Tom stares, open-mouthed.

‘Please, Tom, we need to run.’

David stops moving his head and charges at me. I rest my weight on my back leg and find my stance, ready to throw him, but I don’t get the opportunity. Tom hurls himself at the boatman, grabbing him around the waist and shoving him into the metal rail behind. The older man straightens and rubs his back. I think he’s returned to normal, but then he sees me and his face twists with malice.