The result was Dr Jennifer Vaughan, a ferociously clever white woman from Newport who had entered medical school with high hopes of becoming a healer only to find that the puzzle was more interesting than the person, and she found herself gravitating downwards towards the morgue and a career in pathology. I knew way more about her life than she would have been comfortable with, including the time she’d nearly been cautioned for breaching the peace at the Supakart Centre in Newport, because I was the one who’d had to carry out the vetting process. It was your basic Baseline Personal Security Standard (BPSS) vetting that all civil servants had to undergo, plus a few extra bits we’d tacked on to cover what coppers like Seawoll liked to call ‘weird bollocks’.

I didn’t actually ask whether she herself or any member of her family had ever been a fairy, but I skated pretty close. It didn’t help that she had the kind of Welsh accent that made her sound like she was being sarcastic even when she wasn’t.

‘Are my swimming habits really a concern to the Metropolitan Police?’ she’d asked during one of the three interviews I’d conducted. I told her she’d be surprised.

‘I certainly hope so,’ she’d said. ‘Otherwise this will all have been a bit of a waste of time, won’t it?’

If you want to get the full force of her actual sarcasm, for comparative purposes, get her started on the mischaracterisation of hyperthaumaturgical degradation as a cerebrovascular disorder, strokes, aneurysms and the like, when it was quite obviously caused by direct physical trauma to the brain.

‘Admittedly, many of the signs do mirror those we see in stroke victims,’ she’d said. ‘But that’s no reason to be making assumptions, see. Especially when you have such nicely prepared brain sections to examine.’

Luckily me and Guleed weren’t subjected to your actual slices of Christina Chorley’s brain, because Dr Vaughan had already prepared a series of images which she showed us on her tablet. Even better, we were at the Ian West Memorial Forensic Suite at Westminster Mortuary which had a glassed-off observation room which meant that we didn’t have to smell the bodies either. Trust me, this is a bonus even with a nice fresh corpse like Ms Chorley.

I introduced Guleed to the doctors Vaughan and Walid. They shook hands and then Dr Walid leant casually against a work surface with his arms folded and watched while Dr Vaughan took us through her findings.

‘This was the cause of death,’ she said pointing to a smudge.

I caught Dr Walid’s eye and asked if it was a cerebral aneurysm.