Even in these days of eBay and superencrypted anonymous purchasing over the internet, the safest way to buy stolen stuff is to meet a total stranger and hand over a wedge of untraceable readies. They don’t know you, you don’t know them – the only problem is where to meet. Every market needs its place and in London such illegal venues have been called nazareths since the eighteenth century. The goods on sale feed into the twilight economy of the street market, the second-hand shop and the man you met in the pub. There’s more than one, obviously, and they lurch around the city like a drunk banker on bonus day – you have to know someone who knows someone to find them. When things fall off the back of a lorry, a nazareth is where they end up.

This place, I suspected, was a nazareth for things that were a bit too odd to be travelling by lorry in the first place.

The next stall sold death masks done in the Roman style and cast in delicate porcelain so that placing a candle behind them would bring their features to flickering life.

‘Anyone famous?’ I asked the reassuringly modern goth girl who ran the stall.

‘That’s Aleister Crowley,’ she said pointing. ‘That’s Beau Brummell and that’s Marat – he got stabbed in the bath.’

I took her word for it, because they all looked the same to me. Still, I allowed my fingertips to brush the edge of the Crowley mask, but there wasn’t any vestigium. Fraudulent even in death.

‘God, listen to that,’ said Lesley.

I looked back at her. She had her head cocked to one side, a look of amusement on her face.

‘What?’

‘The music,’ she said. ‘They’re playing Selecter.’

‘Is that what this is?’ I asked. It just sounded like generic ska to me.

‘This is my dad’s music,’ she said. ‘If the next thing they play is Too Much Pressure then I’ll know they’re just working their way down his favourite play-list.’

The next song was Too Much Too Young. ‘The Specials,’ said Lesley. ‘Close enough.’

We checked the other stalls but didn’t find anything in the way of stoneware fruit bowls or statuary, though I did make note of a tarot deck imbued with enough vestigium to keep a family of ghosts in operation for a year.

‘Is it relevant to the case?’ asked Lesley.

‘Not really,’ I said.

‘Moving on,’ said Lesley.

‘Where to?’

Lesley pointed to the makeshift balconies above us.

I grabbed the ladder to the next level and gave it a shake. It was as securely fastened as a filing cabinet in a health and safety office. I went first. Halfway up I heard Lesley gasp. I stopped and asked what was wrong.

‘Nothing,’ she said. ‘Keep going.’