‘If their bodies had been found sooner, Ben, toxicology might have established whether they were crystal meth users. But at the moment, we can’t say one way or the other.’

‘They were most likely working there, don’t you think? Producing the methamphetamine.’

‘Slave labour of some kind, yes. The gangs who run these operations are ruthless.’

‘Are we talking about the same people who shot Tom Farnham, do you think, sir?’ asked Cooper.

‘Well, Ben, when these people have a dispute they don’t go to court. They have their own ways of sorting things out.’

Cooper turned to the last page of the intelligence bulletin, which was headed ‘Common Side Effects’. Again, his brain could hardly take them all in. Diarrhoea, nausea, loss of appetite, insomnia, tremors, irritability, weight loss, depression. The list was endless. Why would you risk doing all these different kinds of damage to your body? An overdose could cause brain damage, hallucinations, paranoia, kidney damage and something called formication, described as the sensation of your flesh crawling with insects.

But Cooper’s eyes were drawn to the most peculiar symptom of chronic methamphetamine use of them all. The report referred to a dry mouth, excessive thirst triggering frequent consumption of high-sugar drinks, tooth grinding and the decreased production of acid-fighting saliva. Together, they caused the symptoms of rapid tooth decay. Sometimes known as ‘meth mouth’.

One way or another, methamphetamine had killed Nadezda Halak.

Without her phone for about an hour and a half, Fry felt lost. She stared out of the window of the plane at the Irish Sea passing below. It looked grey, and very wet. She hoped that Ireland itself would be more welcoming. Break out the Guinness and the shamrock, we’ve got a visitor. Oh, yes, that’s how it would be.

Well, it couldn’t be worse than Rakedale. If she’d been forced to spend another day in that place, she would probably have gone mad, even without the effects of the toxic chemicals on her body.

For a moment, Fry wondered whether she could sue Derbyshire Constabulary for not providing her with proper protective equipment to do her job. Yes, probably. Health and Safety regulations called for a risk assessment, which hadn’t been carried out, so far as she was aware.

But all she had was this damn cold to show for it. And no doubt she’d discover that the officer who ought to have carried out the risk assessment was her.

But Rakedale was definitely her idea of one of the outer circles of Hell. The people who lived there were slightly less than human, dead to normal standards of civilized behaviour.

Fry had once heard of a rare medical condition that destroyed the sense of touch. When you had the condition, it became impossible to tell sandpaper from silk, leather from stone, or water from oil. Impossible to feel anything at all.