The following day the cross-examination proceeded. The accused had little difficulty in dealing with the early matters put to him Suddenly he was asked, ‘How long have you known Owen McGuire?’

‘Who?’

‘Owen McGuire. How long have you known him?’

‘I don’t know anybody called Owen McGuire. I’ve never heard of Owen McGuire.’

‘Please be very careful. Have you had any dealings of any kind with someone called Owen McGuire or who uses the name Owen McGuire?’

‘I am being careful. Very careful. Now watch my lips. I have never met, dealt with or heard of someone called Owen McGuire, Owen anything or anything McGuire. Is that clear enough for you? Is that being careful ?’

Looking decidedly puzzled, the advocate depute realised it was time to move on to potentially more fruitful ground.

He would have been even more puzzled if he had glanced at his opponent. Muirhead’s expression was a bizarre mixture of amusement and rage. Owen McGuire was a figment of his imagination.

From that day forth, he had a deep and abiding dislike of the telephone. He did not trust it, or rather did not trust the people who might be listening in to it. Hence he wanted to meet Jack Morton face to face.

‘As you please. Tomorrow night. Six o’clock. My office.’

‘Suits me. I’ll arrange for Donald Anderson to be there.’

‘Things are getting interesting, n’est ce pas?’

‘Ain’t they just.’

‘See you tomorrow night.’

Muirhead sank back into his battered old armchair and began the ritual of emptying, filling and lighting his favourite pipe.

The preparation of the case was well under way and in his study he was surrounded by bundles of papers, maps and photographs. He had already identified the various areas of potential difficulty as well as the parts of the evidence which could assist the defence. In his mind he was developing the possible strategies which might be available to tackle the prosecution case.

Grasping the defence case had not proved overly taxing. The client knew nothing about either crime and was claiming to have been at home when each murder was committed. He had been surrounded by members of his family and a variety of friends and acquaintances, each of whom was more than willing to testify to this effect. That was the easy bit.

Muirhead did not go into trials with a detailed battle plan. His preparation was faultless and he would be familiar with all the minutiae of the case. He would know the strengths and weaknesses and would have worked out how to highlight the former and paper over the latter.

Once the trial started he did not rely on preconceived notions. He had to be able to react to events as they happened, deal with evidence as it appeared, expect surprises at every turn. If a plan went awry, it was all too easy to find himself with nothing to fall back on.