‘I thought I was ready for the rural life ...’

‘In Currie?’

Hogan sounded sceptical.

Colquhoun tipped his head. ‘I eventually realised my mistake.’

‘And moved to Duddingston.’

‘Not at first. I rented a few properties while I was looking for a place to buy.’

‘Mr Lintz has your telephone number in Currie, but not for the Duddingston address.’

‘Interesting. I went ex-directory when I moved.’

‘Any reason for that, sir?’

Colquhoun swayed in his chair. ‘Well, I’m sure it sounds awful . . .’

‘Try us.’

‘I didn’t want students bothering me.’

‘Did they do that?’

‘Oh, yes, phoning to ask questions, advice. Worried about exams or wanting deadlines extended.’

‘Do you remember giving Mr Lintz your address, sir?’

‘No, I don’t.’

‘You’re sure of that?’

‘Yes, but it wouldn’t have been hard for him to find out. I mean, he could just have asked one of the secretaries.’

Colquhoun was beginning to look more agitated than ever. The little chair could barely contain him.

‘Sir,’ Hogan said, ‘is there anything you want to tell us about Mr Lintz, anything at all?’

Colquhoun just shook his head, staring at the surface of his desk.

Rebus decided to use their joker. ‘Mr Lintz made a phone call to this office. He was talking for over twenty minutes.’

‘That’s ... simply not true.’

Colquhoun mopped his face with a handkerchief. ‘Look, gentlemen, I’d like to help, but the fact is, I barely knew Joseph Lintz.’

‘And he didn’t phone you?’

‘No.’

‘And you’ve no idea why he’d keep note of your Edinburgh addresses for the past three decades?’

‘No.’

Hogan sighed theatrically. ‘Then we’re wasting your time and ours.’

He got to his feet. ‘Thank you, Dr Colquhoun.’

The look of relief on the old academic’s face told both detectives all they needed to know.

They said nothing as they walked back downstairs - like Colquhoun had said, sound could travel. Hogan’s car was nearest. They rested against it as they talked.

‘He was worried,’ Rebus said.

‘Hiding something. Think we should go back up?’

Rebus shook his head. ‘Let him sweat for a day or so, then hit him.’

‘He didn’t like the fact you were there.’

‘I noticed.’

‘That restaurant ... Lintz dining with an elderly gent.’

‘We could tell him we’ve got a description from the restaurant staff.’

‘Without going into specifics?’

Rebus nodded. ‘See if it flushes him out.’

‘What about the other person Lintz took to lunch, the young woman?’

‘No idea.’

‘Posh restaurant, old man, young woman ...’

‘A call girl?’

Hogan smiled. ‘Do they still call them that?’

Rebus was thoughtful. ‘It might explain the phone call to Telford. Only I doubt Telford’s daft enough to discuss business like that from his office. Besides, his escort agency runs from another address.’

‘Fact is, he called Telford’s office.’

‘And nobody’s owned up to talking to him.’

‘Escort agency stuff, could be very innocent. He doesn’t want to eat alone, hires some company. Afterwards, a peck on the cheek and separate taxis.’