In many criminal investigations there are suggestions of witnesses being intimidated, usually in an attempt to prevent them speaking to the police. It was quite novel to hear a witness claim that she had been forced to give evidence against an accused. Someone, somewhere clearly had an interest in getting Gallagher done. But who and why? If the two men with the Irish accents were one and the same person, he would like to find him – maybe. Maybe not. One day down and still he had no notion of the connection between the two murders – up to now. But now there was the germ of a connection – the mystery man with the Irish accent. Somewhere in the papers he had seen another reference to an Irishman. For the moment he could not recollect where. He would find it later.

As he turned into Allison Street there was a loud bang as the car pitched down at the front and lurched to the nearside. Muirhead fought for control but there was no response. He hit the brakes and the car came to an abrupt halt. Fortunately, no one was coming towards him and, other than banging against the kerb, he thought he and the car had survived relatively unscathed.

As he checked round about him he looked in his rear-view mirror to see a car behind him swerving to avoid an object lying in its path.

‘What in the name of God is that?’ he muttered. As he got out of the car to check for the damage, he found out.

The Jaguar was minus a front wheel.

Chapter Six

The second morning of the trial was taken up by the pathologists.

Pathology is the strangest of medical specialities. Its practitioners spend their time surrounded by dead, mutilated bodies. Confront them with a living specimen and they run the proverbial mile. A pathologist encountering a child with a grazed knee could tell the angle of the wound, its age and the nature of the surface which caused the damage, but would not have a plaster to stick on it.

Julian Walker was the Regius Professor of Forensic Medicine at Glasgow University. He was a small, dapper man who habitually wore a spotted bow tie. As he gave his evidence he peered over the top of his gold-rimmed half-spectacles. His enthusiastic performance conveyed the impression of a man who loved his work – strange as that work might be.