He waited for a while, mesmerised, until the blood flow slowed before checking her pulse. She was still alive, just. He grabbed her hair and pulled her head up so that he could look in her eyes one last time. Pushing her chin down roughly, he took hold of her tongue, his hands slipping on a mix of saliva and blood. He took the machete once more and cut it out. He put it in a clear, zipped bag and stuffed it in the front of his backpack. He took one more look at her as the life ebbed away from her body and then he left. She’d brought this on herself. Now he could stop. But would he?

‘Jesus,’ Liam says. ‘Grim. So this is the source material for Anna’s murder?’

‘It would seem so. It’s from a book called The Threat by E. F. Bennett. It did tremendously well for a debut novel and the film rights were sold almost straight away. The Threat became Blood Ice. Two more books were released in The Threat series; The Violent Threat and The Final Threat.’

‘Which means, if the killer is using these books as a blueprint, we could potentially have 2 more murders?’

‘That’s assuming he only picks one death from each book.’

Liam lowers his gaze to the page again. He holds it up for me to look at.

‘Why do you reckon he has highlighted through her clothes?’ he asks.

I point at the other words on the page that have been singled out. ‘Tongue and cut it out have been highlighted too. At first I wasn’t sure but then I thought about what you said about the film.’

‘That she was naked?’

‘That, yes, and also that her tongue wasn’t cut out. I think the highlighted sections are the differences between the film and the book, and therefore the film and the real-life murder.’

He scans the page again and seems to agree with my hypothesis.

‘Why would he leave this at the crime scene?’ he wonders aloud, but more to himself.

I shrug my shoulders and take a sip of the coffee. The warmth seeps down my throat and spreads through my body.

‘Do you think the killer is one of those geeks who watches a film with a notebook and logs inaccuracies on the internet?’

Liam takes out his phone and taps the screen a few times. He raises his shoulders and tilts his head, adopts a nerdy voice; ‘Ah, during the 1972 New Year’s Eve celebrations, Forrest Gump drinks a Dr. Pepper with a logo that wasn’t devised until the mid-1980s.’

He pushes imaginary glasses up his nose to emphasise the point.

‘Someone actually wrote that on the internet?’

‘Yeah, clearly a psychopath,’ he laughs.

Glancing outside, I notice that the rain has relented somewhat and suggest getting back on the road. Liam nods his agreement and we return to the car, coffees in hand.

‘It’s about 45 minutes from here to Conwy,’ I say, as I restart the sat nav.