‘You don’t want this to go to court,’ said Ross. ‘You don’t want your customers seeing you in the dock, hearing about you being cross-examined, wondering just how many of the community’s secrets you’ve given away. I mean, it’s not like they’re onside with you now, is it?’ She brought to mind the image of the barmaid’s blank features, of how Keel had injured her. ‘You don’t want to lose face.’

Keel considered for a moment. Then he lowered his head. ‘At least you’re in the circle,’ he said. Then he sighed, as if he was talking to children. ‘I mean,’ he translated, ‘the M25. Used to be the North Circular.’

‘The traditions change with the times,’ said Sefton.

Keel looked as if he wanted to spit at him. ‘What do you want to know?’

Ross slapped a printout image onto the table. It showed the mirror standing on the grass outside the Portakabin.

Keel looked puzzled at it. ‘Ordinary mirror. Nothing of my world about that. And I’ve seen it all.’

Ross looked to Sefton, who nodded. That only confirmed what they’d already thought. The idea that the Ripper might have come out of it because of the nature of the object itself had been a long shot.

‘What about the Bridge of Spikes?’ said Costain.

Ross saw Sefton’s expression change. He wouldn’t say anything in front of the suspect, but he was obviously wondering why Costain was asking about something of which he had no knowledge. She and Costain had talked beforehand about this. They might never get the chance to be alone with Keel.

‘What about it?’ said Keel.

Oh, he knew about it. He actually knew! Ross felt the tension in her own chest and appreciated the way Costain was keeping his tone level. ‘Have you ever seen one?’

‘There is only one. And, no, I haven’t. When that was sold at auction, the bidding went on all night. It went into some terrible fucking places. Too rich for my blood.’

‘Is there anything else that does the same job?’

‘Of course there fucking isn’t.’

Ross felt her hope fall away and hit the next level down, like a ball dropping through a maze. Okay. They would just have to find whoever had stolen it from the flat. It would take time, but that would be her life now – the life of both of them, together. She could accept that.

‘Have you ever seen a scrying glass?’ asked Sefton, trying to get back to the plan.

‘Yeah, once. They’re not unique like the Bridge, but they’re pretty rare.’

‘Where did you see it?’