‘What if the path goes over the edge of a cliff, Daddy?’ asked Bertie, his voice seeming to echo in the swirling mist.

‘Highly unlikely, Bertie,’ said Stuart. ‘Paths don’t go over cliffs; they follow the contours of the hill. That’s what we’re doing right now, and any moment now we shall find ourselves on the A702. Then we shall simply walk back to Flotterstone, retrieve our car, and travel home to Edinburgh. Have courage, Bertie.’

Bertie swallowed. Having gained height, they were now losing it again, but the vegetation around them had changed. Heather had given way to pasture, and there was a drystane dyke looming up through the white porridge of the haar.

‘We’ll follow this dyke,’ said Stuart. ‘Dykes always go somewhere, Bertie – that’s a tip for you to remember. I shouldn’t be surprised if this dyke doesn’t lead to a farm somewhere. And farms always have tracks that take you to public roads. So we’ll be fine – you mark my words.’

They walked on. The haar was lifting slightly now, and ghostly trees began to make themselves visible. And then, as they surmounted a small knowe, they saw lights in the middle distance. A few yards later and the lights were shown to be coming from a farmhouse, to the rear of which was a small cluster of trees and a steading.

‘There you are, Bertie,’ said Stuart. ‘Right on cue: a farmhouse. We can ask directions there – not that I think we’re really lost.’

They approached the farmhouse, a comfortable-looking building with white harling and blue-painted doors and window frames. Stuart went up to the front door and knocked loudly. Inside the porch a light was switched on and there was the sound of an inner door being opened. A woman appeared, dusting her hands on a white apron tied around her waist.

‘Sorry to disturb you,’ said Stuart. ‘But I think that we’re a bit lost. We’re trying to get to Flotterstone.’

The woman smiled. ‘Well, you’re very lost, if you ask me. Flotterstone is way over that way – behind the hill.’

‘Ah,’ said Stuart. ‘I see.’

The woman looked past Stuart. ‘And there’s your wee boy. My, he looks a bit bedraggled. I think you should come away in and I’ll make you a cup of tea.’

Stuart thanked her, and he and Bertie went inside, removing their boots and leaving them in the front porch alongside a collection of well-used farming footwear.

‘I have a son about your age,’ said the woman to Bertie. ‘He’s called Andy. We call him Wee Andy because his father’s called Andy too. What’s your name?’

‘Bertie. I’m Bertie Pollock.’

‘Now that’s a fine name,’ said the woman. ‘I know some Pollocks. They farm over at Muckle Buggie. You’re not related to them, are you?’

Stuart shook his head. ‘We’re Scotland Street,’ he said.