As the sun set, the detector at Croft Ambrey went offline and we called Stan, who lived close by in Yatton Marsh, to see whether she’d noticed anything. Dominic shouted into the phone for Stan to turn the music off but to no obvious success. He grimaced and turned the phone in my direction so that I could hear a burst of a raw sounding cover of Children of the Revolution before Dominic cut the line in disgust.

‘She’s been sniffing aggro diesel and listening to 9XDead again,’ he said. ‘There won’t be nothing coherent from her until Wednesday.’ He put the phone away. ‘Do we actually have an operational plan for dealing with the unicorns?’ he asked, and then laughed. ‘I can’t believe I just said that.’

‘Priority one, protect members of the public,’ I said. ‘Priority two, if we can, follow them back to wherever it is they come from in the hope that we can recover the real Nicole.’

Dominic decided to risk a dash for some drinks. While he was away I amused myself by piggybacking onto the Laceys’ wifi and looking at the online newspaper front pages. The Express went with a new Diana conspiracy theory, the broadsheets went with Syria and a side order of fracking, the tabloids with cricket and the Royals. Windrow had been right. Sharon Pike’s little meltdown was being quietly forgotten. It made sense. No profession likes to wash its dirty laundry in public.

Nightingale called at last.

They’d triangulated the signal from Lesley’s phone to a flat in the Dog Kennel Hill estate in Dulwich, and after the requisite amount of time charging about shouting ‘police’ and ‘clear’ Nightingale had walked into the kitchen to find an envelope on the table with his name on it.

‘It was one of those white envelopes you get with greeting cards and inside was one such, with a cat on the front licking its paw and the inscription With Sympathy in pink letters. Inside were written the words NICE TRY.’

‘I told you,’ I said.

‘She could have left us a demon trap,’ said Nightingale. ‘Or something mundane and equally unpleasant. It’s quite maddening, really. I’m certain she’s trying to communicate something to us, but I’m damned if I know what. Did she say anything significant to you on the phone?’

‘I’d rather tell you about that call in person,’ I said.

‘Quite,’ said Nightingale. ‘How are things your end?’

I gave him a quick briefing.

‘I think things may be kicking off soon,’ I said. ‘I could use some help.’

‘I’ll set off as soon as I’m sure that Lesley has really left the area,’ he said. ‘That should put me in your vicinity in four to five hours. Can you last until then?’

‘Yes, sir,’ I said.