I called up Leominster nick and they confirmed that while they’d had trouble getting a precise DNA match between the blood stain on the pink cotton with hair samples recovered from Nicole’s room, a second round of tests using swabs taken from Victoria and Derek Lacey had confirmed a definite parental match. The high probability, the lab had said, was that the blood had belonged to Nicole Lacey.

Which meant that they had gone west down either the Mortimer Trail or the logging road that ran parallel to it, and had probably stayed in that area for at least three days before Nicole had caught her leg on the barbed-wire fence above Pokehouse Wood. A place famous as the abode of fairies – and a mere hop, skip and a jump from where we’d found the dead sheep.

I called Dr Walid and asked whether he’d finished his autopsy.

‘Hello, Peter,’ he said. ‘How’re you bearing up?’

I told him I was fine.

‘Wonderful bit of mutton you sent me,’ said Dr Walid. ‘Finished it up this morning. Thought you might like the results.’

‘Anything interesting?’

‘The sheep itself is your bog standard North Country Mule, a cross between Swaledale and a Border Leicester – a breed known for its meat and for being even more gleckit than ordinary sheep. I’ve sent some tissue samples to the lab just to be sure.’

‘Any sign of magical contact?’

‘Nothing in gross physical terms. I sectioned the brain, such as it was, but there was no sign of hyperthaumaturgical degradation. It was a remarkably healthy sheep – apart from the great big hole in its belly, of course. That was cause of death, by the way. In case you were wondering.’

‘Could you reconstruct the injury?’

‘Well, it’s never easy just going by the crime scene photographs. But at a guess I’d say it was struck in the belly, impaled, then lifted bodily and thrown some distance. That’s how its guts got spread over such large area.’

‘Are you saying it was gored?’ I asked. ‘By a bull or a goat?’

‘I’ve met some tough goats, but nothing big enough to fling a full grown sheep three metres or so,’ said Dr Walid. ‘And there’s only one piercing wound, so I doubt it was a bull or even a cow – they can get quite territorial, you know.’

I asked what the weapon had been like.

‘At least sixty centimetres long, circular cross section and tapering to a sharp point,’ said Dr Walid. ‘Possibly a spiral configuration.’

‘Like a narwhale’s horn?’

‘Aye,’ said Dr Walid. ‘Just like that.’

‘So you think it’s a unicorn?’

‘I wouldn’t like to jump to conclusions,’ he said. ‘Not without more evidence.’

‘But?’

‘If you achieve nothing else,’ he said, ‘get me a tissue sample.’