‘If it’s him, he deliberately used that message at the crime scene to send us on the wild goose chase of Ripper lore. He would have known from our memories that we didn’t know what a scrying glass looked like, and that even when we found out, we’d assume he was the one who’d been played. It all fits. He tailored the fiction precisely to what he knew about his audience.’

‘Just like he does with his newspapers,’ said Costain.

Sefton made a noise as if he’d suddenly realized something. ‘That PA,’ he said, ‘Vincent had her be there when we visited him, so she could confirm his story about the Ripper coming out of the mirror. She never said she saw the Ripper himself or anything happening with the mirror. It was all over by the time she got into the room.’

‘Still,’ said Ross, ‘I don’t believe he was that far-sighted that he staged something to set up his story way back then. Something violent happened to him in that room.’

‘And there were genuine traces of the silver goo,’ said Sefton, ‘which Vincent apparently couldn’t see first-hand, only, I suppose, when he saw our memories of it.’

‘He was cocky enough to try to play us face to face,’ said Ross, ‘when everything else about him says he’s cautious. Why?’ She suddenly pointed at the other two. ‘Because he wanted something from us. What did he say to us? What did he ask?’

Sefton found his notebook. ‘He asked whether or not we could … find a missing person using gestures, and if we had any defence against scrying glasses. He must have known we didn’t have the answers right then, but … oh fuck, I know what this was: he wanted us to go away and find out, and then he could look into our frigging brains like we were his own private Wikipedia!’

‘At least,’ said Costain, ‘we didn’t take him up on those suggestions.’

‘I would have got there with the defences bit,’ said Sefton. ‘And then he’d have known how to get round them, for anyone else’s brain he wanted to look into, if they tried to block him. Shit.’

‘So who would he be looking for?’ asked Ross.

‘You said you thought the man that was killed in the Soviet bar, Rudlin, wasn’t the target, that it was actually Mary Arthur,’ said Costain. ‘If Vincent is the one controlling the Ripper or being the Ripper or however it works, she got away from him that night.’

Ross acknowledged that with a frantic nodding. She fell silent for a moment, no longer able to control the movements of her hands as they flexed in the air, the product of her ferocious thinking.

Sefton hauled himself up and paced the confines of the van, looking more horrified every moment as the implications sank in.