Clay pictured Annie’s mother and father sitting in the public gallery as this information emerged in court and felt a weight like a paving stone sink to the core of her being.

She imagined the months and years following, their sleepless nights as the information played out in their heads, each time the horror never diminishing, each time falling further down a bottomless pit of grief.

‘I’ll confirm the cause of death as strangulation by taking out her larynx and hyoid bone. Deep tissue contusion and fracture damage to the laryngeal bone will confirm the external evidence of strangulation. Then, we’ll have to open her up and assess the contents of her stomach and internal damage, if any.’

Clay’s iPhone vibrated on a nearby aluminium table, rattling the metal with each pulse.

‘Better get it, Eve,’ said Doctor Lamb.

She saw COLE on display, connected the call.

‘Barney?’

‘I’ve had a call from DCI Dave Ferguson, SIO on the Sandra O’Day case in Warrington. He wants to know when you’d like him to travel in to see you?’

‘Ask him when he can make it in.’

‘I already have done. He can be there in three hours.’

‘Tell him I’ll be there and thank you very much.’

As she placed her iPhone back on the aluminium table, there was a tentative knock on the door. A middle-aged man in blue scrubs entered the autopsy suite carrying a brown envelope in his hands, trying hard to look anywhere except at the dead woman on the table.

‘I’m William Wilson,’ he said. ‘I’m Annie Boyd’s dentist.’

His compulsion to see overwhelmed his instinct to look away. Clay drank in the expression on the dentist’s face as he looked at Annie’s body with growing horror and disbelief.

‘Jesus,’ said the dentist. ‘Poor woman. Poor Annie. My God.’

‘When did you last see her, Mr Wilson?’ asked Clay.

‘Last week. Tuesday. I whitened her teeth.’

Pearly whites, for the benefit of the man who went on to kill you, thought Clay.

‘What’s in the envelope, Mr Wilson?’ asked Clay, showing him her warrant card.

‘My notes on Annie’s teeth and her dental X-Rays.’

‘Can you send a copy of your notes to Detective Constable Barney Cole at Trinity Road police station, please.’

‘Harper,’ said Doctor Lamb. ‘Show Mr Wilson her teeth.’

As Harper pulled her mouth open, the dentist approached, looked closely at the dead woman’s teeth for many moments.

‘It’s Annie Boyd. She had a V-shaped indentation on her upper left canine.’ He turned to Doctor Lamb. ‘Do you have access to a mobile X-Ray machine?’

‘I’ll request one from the Dental Hospital.’

‘I’ll confirm it beyond any doubt using that.’

‘William,’ said Clay. ‘I’m going to have to communicate this information to family liaison. They’re going to have to break it to her parents…’