Ross got an email and recognized the name. ‘The first of those victims,’ she said, feeling as if they were rats being pursued into a corner, ‘that’s the person the Royal Albert Hall say purchased the ticket for Challoner tonight.’ She slammed the seat with her fist. ‘No wonder the Herald kept pushing the “mob did it” angle about the killings. Vincent used them as cover for every murder. And tonight he’s got that cover just about everywhere.’

*   *   *

They reached the mews flat and parked outside. It was silent and dark, and through the windows that didn’t have curtains they could see only empty rooms. An estate agent’s board indicated it was for sale. They could hear the distant sounds of chaos moving closer. Costain felt a helpless fury marching back and forth inside him as he looked up at the building. The billionaire had many properties, in London and round the world. He also had an organization which could keep the Met in general – never mind one small unit with a bizarre story – at bay forever. He’d had a good long look at the way Costain’s team did things and had used tonight to make any possibility that they might get him into court recede into the distance at the speed of light. Even the phone number Vincent had given to the Quills didn’t connect now. Mary Arthur might have gone into hiding, never to be heard from again.

Eventually they would sleep.

‘There’s been a Ripper attack in Manchester,’ said Ross, looking up from her phone. Costain went over to see, while Sefton went across to try the door of the building. The story checked out, the MO just the same. As they’d suspected, Vincent could reach them even if they fled London. Their only chance was to hide, to give his vast media network, used to pursuing disgraced celebrities, no clue as to where they were. They might need to live the rest of their lives in fear.

Again Costain considered his options. As terrible as it was, as horrifying as the line of dominoes that would now fall would be … he now had no alternative. He’d made his decision.

‘I’m sorry,’ he said to Ross.

‘What for?’

‘I have to go.’

She had a look of perplexed horror on her face. He didn’t let it get to him. He would see much worse soon. ‘What? No! We can’t split the team up now…!’

He kissed her again, against her words, held her tightly to him, despite her moving away, her needing to know what he was going to do. He drew comfort from her and desperately wished he could offer some in return.

‘I’ll come back, I promise.’