There’s a noise outside. It’s a strange noise, a keening. It sounds more human than animal – but at the same time it doesn’t sound entirely human either. In our bedroom, Freddy and I look at one another. All the guests have gone to bed too, about half an hour ago now. I thought they would never get tired. We had to wait until the bitter end in case they needed anything of us. We listened to the drumming from the dining room, the chanting. Freddy, who has a little schoolboy Latin, could translate the thing they were chanting: ‘If I cannot move heaven, I shall raise hell.’ I felt the gooseflesh rise on my skin at that.

They’re like overgrown boys, the ushers. I’d say they lack the innocence of boys: but some boys aren’t ever really innocent. What I mean is that as grown men they should know better. And there is a pack feeling about them, like dogs that might behave well on their own but, once all together, don’t have their own minds. I’ll have to keep my eye on them tomorrow, make sure they don’t get carried away. It is my experience that some of the smartest affairs, populated by the most well- heeled and upstanding guests, have been those that have got most out of control. I organised a wedding in Dublin that contained half Ireland’s political elite – even the Taoiseach was there – only for things to come to blows between the groom and father-in-law before the first dance.

Here there’s the added danger of the whole island. The wildness of this place gets under your skin. These guests will feel themselves far from the normal moral codes of society, safe from the prying eyes of others. These men are ex-public schoolboys. They’ve spent much of their lives being forced to follow a strict set of rules that probably didn’t end with their leaving school: choices around what university to attend, what job to do, what sort of house to live in. In my experience those who have the greatest respect for the rules also take the most enjoyment in breaking them.

‘I’ll go,’ I say.

‘It’s not safe,’ Freddy says. ‘I’ll come with you.’ I tell Freddy I’ll be fine. To reassure him I tell him I’ll pick up the poker from beside the fire on my way out. I’m the braver of the two of us, I know. I don’t say this with any great pride. It’s simply that when the worst has happened, you rather lose your fear of anything else.

I step into the night, appreciating the quality of the darkness, the velvet black as it folds me into itself. Any light from the Folly makes very little impact upon it, though the kitchen is aglow – and also one of the upstairs windows, the room the soon-to-be-married couple are occupying. Well, I know what’s keeping them up. We heard the rhythmic shudder of the bed against the floorboards.

I won’t use the torch yet. It will make me stupid in the darkness. I stand here, listening intently. All I can make out at first is the slam of the water on the rocks and an unfamiliar, susurrating sound which I finally identify as the marquee, the fabric rustling in the gentle breeze some fifty yards away.

And then the other noise begins again. I’m better able to recognise it, now. It’s the sound of someone sobbing. Man or woman, though, it’s impossible to tell. I turn in its direction and as I do I think I catch a shimmer of movement out of the corner of my eye, in the direction of the outbuildings behind the Folly. I don’t know how I saw it, it being so dark. But it is hardwired into us, I think, into our animal selves. Our eyes are alert to any disturbance, any change in the pattern of the darkness.

It might have been a bat. Sometimes in the early evening you can see them flit above in the twilight, so quick you’re not sure you’ve seen them. But I think it was bigger. I’m sure it was a person, the same person who sits weeping cloaked in darkness. Even when I came here all those years ago, even though the island was inhabited then, there were ghost stories. The grieving women mourning their husbands, brutally slain.

The voices from the bog, denied their proper burial. At the time we scared ourselves silly with them. And in spite of myself I feel it now, the sensation of my skin shrinking over my bones.

‘Hello?’ I call. The sound stops, abruptly. When there is no answer I click my torch on. I swing the beam this way and that.

The beam catches on something as I move it in a slow arc. I train it on the same spot, and guide it up the figure that stares back at me. The beam marks out the dark wild hair, the gleaming eyes. Like a being straight from folklore – the Pooka: the phantom goblin, portent of impending doom.

In spite of myself I take a step back, the torch beam wavering. But gradually, recognition dawns. It’s only the best man, slumped against the wall of one of the outbuildings.

‘Who’s there?’ His voice sounds slurred and hoarse. ‘It’s me,’ I say. ‘Aoife.’

‘Oh, Aoife. Come to tell me it’s time for lights out? Time to get into bed like a good little boy?’ He gives me a crooked grin. But it’s a half- hearted affair, and I think those are tear tracks that catch in the beam.

‘It’s not safe for you to go wandering around the outbuildings,’ I say, all practicality. There’s old farm machinery in there that could cut a person in half. ‘Especially without a torch,’ I add. And especially when you’re as drunk as you are, I think. Although, oddly enough, I feel as though I am protecting the island from him – rather than the other way round.

He stands up, walks toward me. He’s a big man, drunk and more besides – I catch a sickly-sweet vegetable waft of weed. I take another step away from him and realise that I’m gripping the poker hard. Then he grins, showing crooked teeth. ‘Yeah,’ he says. ‘Time for Johnny-boy to go to bed. Think I had a bit too much of the old, you know.’ He mimes drinking from a bottle, then smoking. ‘Always makes me feel a bit off, having too much of both together. Thought I was fucking seeing things.’

I nod, even though he can’t see me. So did I.

I watch as he turns on his heel and lurches his way towards the Folly. The forced good humour didn’t convince me for a second. Despite the grin he seemed caught between miserable and terrified. He looked like a man who had seen a ghost.