‘Ah, Conor,’ Rebus said now, bowing his head so no passers-by would see the tears forming.

Siobhan was on the phone to the Farmer.

‘It’s good to hear from you, Siobhan.’

‘Actually, I’m after a favour, sir. Sorry to disturb your peace and quiet.’

‘There’s such a thing as too much peace and quiet, you know.’ The Farmer laughed, so she would assume he was joking, but she detected something behind his words.

‘It’s important to stay active.’ She almost winced: it sounded like something from an agony column.

‘That’s what they say all right.’ He laughed again: it sounded even more forced this time. ‘Which new hobby are you suggesting?’

‘I don’t know.’ Siobhan squirmed in her chair. This wasn’t quite the conversation she’d expected. Grant Hood was sitting the other side of the desk. He’d borrowed John Rebus’s chair, which looked like the one from the Farmer’s old office. ‘Maybe golf ?’

Now Grant frowned, wondering what the hell she was talking about.

‘I’ve always said golf spoils a good walk,’ the Farmer said.

‘Well, walking’s good for you.’

‘Is it? Thanks for reminding me.’ The Farmer definitely sounded tetchy; she didn’t know quite why or how she’d hit a nerve.

‘About this favour … ?’ she began.

‘Yes, better ask it quick, before I get my jogging shoes on.’

‘It’s sort of a clue to a puzzle.’

‘You mean a crossword?’

‘No, sir. It’s something we’re working on. Philippa Balfour was trying to solve all these clues, so we’re doing the same.’

‘And how can I help?’ He’d calmed a little; sounded interested.

‘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.’