‘God,’ Jake Harley said, ‘I’ve got too much food here as it is.’

He didn’t look surprised to see Rebus. ‘I thought she’d crack under pressure,’ he said.

‘No pressure necessary, Mr Harley. She’s worried about you, that’s all. I was worried too for a while there – thought you might have had an accident.’

Harley managed a smile. ‘By which you don’t really mean “accident”?’ Rebus nodded. He was staring at Harley, trying to see him as ‘Mr H.’, the person who had ordered Allan Mitchison’s execution. But that seemed way off the mark.

‘I don’t blame you for going into hiding,’ Rebus said. ‘Probably the safest thing you could have done.’

‘Poor Mitch.’ Harley looked down at the ground. He was tall, well built, with short, thinning black hair and metal-rimmed glasses. His face had retained a touch of the schoolboy, but he was badly needing a shave and to wash his hair. The tent’s flaps were open, showing ground-mat, sleeping bag, a radio and some books. Leaning against the interior wall of the broch was a red rucksack, and nearby a camping-stove and carrier bag filled with rubbish.

‘Can we talk about it?’ Rebus asked.

Jake Harley nodded. He saw that Jack Morton was more interested in the broch itself than in their conversation. ‘Isn’t it incredible?’

‘Bloody right,’ Jack said. ‘Did it ever have a roof?’

Harley shrugged. ‘They built lean-tos in here, so maybe they didn’t need a roof up there. The walls are hollow, double-thick. One of the galleries still leads to the top.’ He looked around. ‘There’s a lot we don’t know.’ Then he looked at Rebus. ‘It’s been here two thousand years. It’ll be here long after the oil’s gone.’

‘I don’t doubt that.’

‘Some people can’t see it. Money’s made them short-sighted.’

‘You think this is all about money, Jake?’

‘Not all of it, no. Come on, I’ll show you the Haa.’

So they walked back out into the wind, crossing the grazing land and coming to the low wall around what had been a good-sized stone-built house, only the shell of which remained. They circuited the boundary, Briony walking with them, Jack further back, reluctant to leave the broch.

‘Mousa Broch has always been lucky for the hunted. There’s a story in the Orkneyinga Saga, an eloping couple took shelter here …’ He smiled at Briony.

‘You found out Mitch was dead?’ Rebus asked.

‘Yes.’

‘How?’

‘I phoned Jo.’

‘Jo?’

‘Joanna Bruce. Mitch and her had been seeing one another.’ So at last Braid-Hair had a name.

‘How did she know?’

‘It was in the Edinburgh paper. Jo’s a media checker – she reads all the papers first thing every morning to see if there’s anything the various pressure groups should know.’

‘You didn’t tell Briony?’

Jake took his girlfriend’s hand and kissed it. ‘You’d only have worried,’ he told her.

‘Two questions, Mr Harley: why do you think Mitch was killed, and who was responsible?’

Harley shrugged. ‘As to who did it … I’d never be able to prove anything. But I know why he was killed – it was my fault.’