I've flown round the world chasing zombies and chupacabras, Filipino faith-healers and beasts in Bodmin; I've used glass vials to collect dripping milk from the breasts of Mexican virgin statues — and in that time I've worked up a hard skin. But even I had to admit there was something odd-looking about the Psychogenic Healing Ministries' island. If you were going to believe in devil-worship you'd picture it happening somewhere remote and sea-wreathed like Pig Island. That night, as we jolted and bumped along a dark path that led to the end of the peninsula, I stared out of the window at its dark, desolate shape and for a moment or two there I had to tell myself not to be an old tart about it.

The landlord had crammed me into the back seat of the lobsterman's beat-up rust-bucket of a car. We left the dog in the pub: 'Because he's a mad rocket when he comes out here,' said the landlord, as the car pulled off the road on to a thin, muddy beach. 'Makes him crazy and I'm not putting him in a paddy just because you won't take my word for something.'

We got out of the car and I paused. I hadn't been out on the lash or anything, but I'd sunk a fair old few in the pub and it felt good for a moment to fill my lungs with the night air. The beach was silent, and there was already a breath of autumn in the air. It was gone eleven but Craignish was so far north the sky was still edged with blue. You'd almost think that if you stood on tiptoe and squinted you'd see the land of the midnight sun peeping at you from over the horizon, maybe a reindeer or a polar bear on a giant mint.

'See the pipe?' The lobsterman walked away to the south, totally steady in spite of the whisky, his old shoes leaving dull prints in the mud, his moon-shadow long beside him. 'The wee stank over there?' He was pointing to the long, low shape of a sewage pipe straddling the beach ahead. 'You get the conditions right — a nice westerly, an ebb and a spring tide — then everything from out at Pig Island gets washed up, not in the loch or even on Luing, where you'd expect it, but here, on this side of the peninsula. Most of it gets caught on the other side of that pipe.'