‘Well, sir, the clue goes: “a corny beginning where the mason’s dream ended”. We’re wondering if it might be “mason” as in “Masonic Lodge”.’

‘And someone told you I’m a Mason?’

‘Yes.’

The Farmer was quiet for a moment. ‘Let me get a pen,’ he said at last. Then he had her repeat the clue while he wrote it down. ‘Capital M on Mason?’

‘No, sir. Does that make a difference?’

‘I’m not sure. Usually I’d expect a capital.’

‘So it could be a stonemason or something instead?’

‘Hang on, I’m not saying you’re wrong. I just need to think about it. Can you give me half an hour or so?’

‘Of course.’

‘Are you at St Leonard’s?’

‘Yes, sir.’

‘Siobhan, you don’t need to call me “sir” any more.’

‘Understood … sir.’ She smiled. ‘Sorry, can’t help it.’

The Farmer seemed to brighten a little. ‘Well, I’ll call you back after I’ve given this some thought. No nearer to finding out what happened to her?’

‘We’re all working flat out, sir.’

‘I’m sure you are. How’s Gill coping?’

‘In her element, I think.’

‘She could go all the way, Siobhan, mark my words. There’s a lot you could learn from Gill Templer.’

‘Yes, sir. I’ll speak to you later.’

‘Bye, Siobhan.’

She put the phone down. ‘He’s going to mull it over,’ she told Grant.

‘Great, and meantime the clock’s ticking.’

‘Okay then, clever-clogs, let’s hear your great idea.’

He looked at her as if measuring the challenge, then held up a finger. ‘One, it reads to me almost like a story-line. Maybe from Shakespeare or somewhere.’ A second finger. ‘Two, does it mean “corny” as in old-fashioned, or is it maybe to do with where corn comes from?’

‘You mean where corn was first grown?’

He shrugged. ‘Or how it starts off life as a seed: ever heard the expression “sowing the corn of an idea”?’

She shook her head. He held up another finger.

‘Three, say it’s mason as in stonemason. Could it be a gravestone? That’s where all our dreams end, after all. Maybe it’s a carving of a corn-stalk.’ He bunched the raised fingers into a fist. ‘That’s what I’ve got so far.’

‘If it’s a gravestone, we need to know which cemetery.’ Siobhan picked up the scrap of paper on which she’d written the clue. ‘There’s nothing here, no map reference or page number …’

Grant nodded. ‘It’s a different kind of clue.’ He seemed to spot something else. ‘Could “a corny beginning” actually be “acorny”, as in like an acorn?’

Siobhan frowned. ‘Where would that get us?’

‘An oak tree … maybe oak leaves. A cemetery with “acorn” or “oak” in its name?’

She puffed out her cheeks. ‘And where would this cemetery be, or do we have to check every town and city in Scotland?’

‘I don’t know,’ Grant conceded, rubbing at his temples. Siobhan let the clue drop back on to the desk.

‘Are they getting harder?’ she asked. ‘Or is it that my brain’s packing in?’