I nodded and said likewise. The Corve was a tributary of the Teme – I’d looked up the whole watershed before coming over.

‘Lilly, love,’ called Miss Tefeidiad. ‘Why don’t you be a dear and put the kettle on.’

Something groaned and stirred inside the VW, which rocked alarmingly. I realised then that the back end of the van was dangling over the edge of the bank, as if the ground had eroded away after it had parked.

Beyond where I was sitting a path dropped down to the river, tree roots entangling to form a disturbingly regular flight of steps. At the bottom, the action of the river had carved a pool, deeper and darker than the shallow water immediately downstream. I wondered if the kids playing less than ten metres downstream ever ventured into it for a swim – or what would happen if they did.

A white face appeared in the shadowed doorway of the VW, stared blearily at us from eyes heavily outlined in black, grunted and then swivelled to address the compact cooker that was Germany’s contribution to family holidays in the 1950s.

‘My youngest,’ said Miss Tefeidiad, and got an answering snarl.

‘Don’t mind her,’ said Corve. ‘She’s been like that since Ralph de Mortimer married Gladys the Dark.’

‘So Scotland Yard is back in business,’ said Miss Tefeidiad. ‘Gaily rushing in where even the saints fear to tread.’

I wanted to ask where Beverley was, and how the Teme family just happened to have her phone. But if there’s one thing Nightingale has taught me, it’s to let other people talk themselves out before giving anything away. It’s something he has in common with Seawoll and Stephanopoulos, and all the top cops that I know.

‘I’m just lending a hand with the search,’ I said.

‘For the missing girls?’ asked Corve.

‘Yes.’

‘Well, we haven’t seen them,’ said Miss Tefeidiad. ‘I can tell you that for nothing.’

Lilly’s pale face emerged from the gloom of the camper van and looked around before fixing on me. ‘Do you want sugar?’ she asked. Her left eyebrow was practically hidden behind a row of studs, and loops of silver pierced her left ear from lobe to tip.

‘No tea for me,’ I said. ‘Thank you.’

‘You could have said,’ she snorted, and withdrew.

‘Don’t you go back to sleep now, Lilly,’ said Corve. ‘We still want a cup.’

‘Let me tell you something, Constable Grant,’ said Miss Tefeidiad. ‘Where you are now is not London – it’s not even England.’

‘Yes it is, Ma,’ said Corve.