Challoner made to struggle out of Costain’s grasp, but Costain held on. He must be on the Sighted spectrum. Perhaps that was why Vincent had chosen him. ‘Too late. Chicken run. You reckon he’s coming for us or for you? Tell us something we can use!’

‘He … he makes things happen in London!’ yelled Challoner. ‘He goes on social media, he has all these fake accounts! He uses the Toffs and the skinheads as cover! He starts a riot happening, and then he sends the Ripper to kill whoever he’s after, and then he can blame the Toffs for it! He needs to know roughly where his target is going to be—’

‘You assumed you’d be going to the Proms tonight with Vincent,’ said Sefton. ‘When he didn’t show up, you started to wonder why.’

‘Good little boy stayed in his seat,’ said Ross. ‘You brought Mary Arthur to that bar so that she could be attacked, didn’t you? You kept her there. And then you got out of there, because you knew what was coming!’

‘Yes, yes!’

‘How does it work?’ yelled Sefton. ‘What is the Ripper? How does he control it?’

‘I don’t know. I don’t know!’ Challoner was squirming in Costain’s grip now. The light was getting closer.

‘You can see that, can’t you?!’ bellowed Costain. ‘Will you testify to anything we can get a jury to believe?’

‘Yes! Just, please—!’

Ross looked in the direction of the light again. One of the Toffs was emphasized to her by the Sight, was something extraordinary. It was coming slowly down the steps among the others, moving first to one side, then to another, looking right at the four of them, like a predator sizing up its quarry. She could see the mask clearly now, see the silver falling from its eyes like uncontrollable tears. Suddenly, the figure lurched towards them.

‘Run,’ said Costain.

They sprinted sideways, out of the flow of the crowd down the steps, around the curve of the hall, hauling Challoner along between them. They were aiming for the van parked nearby. Costain was planning to take the wheel, and they would see if the Ripper could match their speed along the empty streets.

But the light was already flaring around the corner of the building. Something shot over their heads.

The Ripper was on them.

It sliced the air with a razor that seemed to cause the air itself to scream and part, like lightning. The first blow cut Costain’s jacket, and he let Challoner go. The man made to sprint away, back into the fringes of the crowd, but before Ross could even shout, the Ripper had spun, leaped up, and come down on Challoner like a cloaked bird of prey as his victim looked up and screamed.