'I'm just saying,' I met his eyes seriously, looking from him to the landlord and back, 'it's got a smell about it, hasn't it? I mean, devil-worshippers? Satan walking the beaches of Pig Island?'

The colour in the lobsterman's face paled very slightly. He crushed the rollie in the ashtray and stood, drawing himself up to his full height. He took a few deep, fighting breaths, and looked unsteadily down at me. 'Laddie, tell me. Are you a man who is easily shocked? You're a big man, but I reckon you're one who'd shock easy. What do ye think?' he said to the landlord. 'Is he? Is he a man who'd go in a funk if he saw something peculiar? Because that's how it looks from where I stand.'

'Why?' I said, putting the glass down slowly. 'Why? What are you going to show me?'

'If you're so clever you don't believe what we're saying, then come with me. We'll see what kind of a hoax is gaun on.'

Pig Island, or as it's called in Gaelic Cuagach Eilean, lies in the small cup of sea at the edge of the Firth of Lorn, caught like a precious stone in a setting between Luing, Jura and Craignish Peninsula — like it's been placed to block the entry to the Sound of Jura. It's a weird shape: like a peanut from above, covered in grassland and dense trees, a wide rocky gorge running down the middle. Once, before the pig farm and the chemical dumping, there'd been a slate mine operating in the south of the island, with a community of miners and a regular ferry. But by the time I got there Pig Island was almost totally cut off. Once a week the Psychogenic Healing Ministries sent a small boat to collect supplies. It was their only contact with the world.

I knew a bit about that part of Scotland — wrote bits and pieces about it from time to time. But my bread and butter was debunking work. One of the things that comes as birthright to a Scouser is knowing the stripe of bullshit when you see it and I'm a natural sceptic, a full-blown non-believer: a Scully, a James Randi, an out-and-out hoax-buster.