‘So,’ Rhona said, ‘do you want to tackle the dress?’

Chrissy thought for a moment. ‘You take the dress and the veil. It feels too close to home for me. I’ll do the shoes.’

‘Jen will want whatever residue you scrape from the soles.’

Chrissy nodded. ‘Roger that.’

Back in the seventies, the idea of soil forensics hadn’t existed and neither had DNA profiling. Rhona recalled an image she liked to use in the Diploma in Forensic Medical Science course she lectured on at Glasgow University, which showed a body on Gullane Beach, east of Edinburgh, in 1977. In it, a row of black-booted police officers stood only inches from one of the female teenage victims in what became known as the World’s End Murders. The current students were so used to seeing carefully protected scenes of crime, peopled by white-suited personnel, that this particular image always brought a gasp of horror from the audience.

Fortunately, soil from one of the girls’ shoes, preserved for future analysis, despite the fact they’d had no idea back then what soil and pollen could reveal, had proved vital in the subsequent historic conviction of the World’s End killer.

With most of the afternoon now gone, Rhona’s detailed and prolonged examination of the underskirt had identified several possible areas of interest, to be cut out and studied in more detail later. As for the actual dress, her initial taping had produced a few dark hairs and unidentified fibres.

‘Coffee time?’ Chrissy called from the office doorway.

Rhona gave her the thumbs up. Progress had been made but there was no doubting the length of time it would take to do the job properly.

The coffee poured, Chrissy now surprised Rhona by producing a box of iced doughnuts.

‘What happened to the healthy diet?’ Rhona said, cheerfully selecting a chocolate-coated delight.

‘Everything in moderation,’ Chrissy announced, choosing one topped with multi-coloured hundreds and thousands. ‘Besides, I needed a sugar rush right about now.’

‘Did you find anything of interest?’ Rhona said.

Chrissy looked solemn. ‘There was soil and pollen on the shoes and material that looked like the remains of gorse flowers. All of which Jen Mackie can give you a better analysis on.’

‘Gorse blooms in May here,’ Rhona said. ‘But Jen’s the expert.’

‘The fingernails snipped at the PM are proving fruitful,’ Chrissy continued. ‘There were deposits of skin and blood on the underside.’

‘So she could have fought her attacker?’

‘Let’s hope so. I’ve retrieved fibres and hairs from the plastic bag, but better than that, a fingerprint.’

Now that was good news.

‘What about the cigarette butt?’ Rhona said.

‘Done. We wait now for the DNA result. Let’s hope whoever did this offended again after we started the DNA database. Otherwise it doesn’t help until we have a suspect.’

They decided to work on for a further hour, and then go for a drink.

‘You never told me what happened with your handsome guitarist,’ Rhona suddenly remembered.

‘All may be revealed over a glass of wine,’ Chrissy promised with a smile.