Siobhan was wearing a vest, polo neck and pure wool V-neck jumper. She had an old pair of thick cords on, tucked at the ankles into two pairs of socks. She’d given her old hiking boots a bit of a polish, and they seemed fine. She hadn’t worn the Barbour in years, but couldn’t think of a better chance to use it. Additionally, she was wearing a bobble-hat, and carrying a pack containing an umbrella, her mobile, a bottle of water and a flask of sweetened tea.

‘Sure you’ve got enough gear?’ Hood laughed. He was wearing jeans and trainers. His yellow cagoule looked brand new. He angled his face to the sun, so that the rays reflected off his sunglasses. They’d parked the car in a lay-by. There was a fence to climb, and after that a gently sloping field which then angled abruptly. The steep gradient was barren, except for occasional whin-bushes and rocks.

‘What do you reckon?’ Hood asked. ‘An hour to the top?’

Siobhan slipped the backpack over her shoulders. ‘With a bit of luck.’

Sheep watched them as they climbed the fence. There was a strand of barbed wire running along it, marked with tufts of grey wool. Hood gave Siobhan a foot up, then leaped over, using his hand on the fence-post for purchase.

‘Not a bad day for it,’ he said, as they started to climb. ‘Reckon Flip would have done this on her ownio?’

‘I don’t know,’ Siobhan conceded.

‘I wouldn’t have said she was the type. She’d have taken one look at this climb and got back into her Golf GTi.’

‘Except she didn’t have a car.’

‘Good point. So how would she have got out here in the first place?’

Which was another good point: they really were in the middle of nowhere, with towns few and far between and only the odd cottage or farm giving signs of habitation. They were only forty miles from Edinburgh, but the city seemed already a distant memory. Siobhan guessed that few buses came this route. If Flip had come here, she’d have needed help.

‘Maybe a taxi,’ she said.

‘Not the sort of fare you’d forget.’

‘No.’ Yet despite a public appeal, and plenty of photos of Flip in the papers, no taxi driver had come forward. ‘Maybe a friend then, someone we haven’t traced yet.’

‘Could be.’ But Hood sounded sceptical. She noticed that he was already breathing hard. A couple of minutes later, he’d shed the cagoule and folded it, tucking it beneath his arm.

‘Don’t know how you can wear that lot,’ he complained. She pulled the bobble-hat from her head and unzipped the Barbour.

‘Is that better?’ she said.

He just shrugged.

Eventually, on the steeper climb, they were reduced to scrabbling with their hands while their feet sought purchase, the stony soil crumbling and sliding away beneath them. Siobhan stopped to rest, sitting down with her knees up, heels digging in. She took a swig of water.