‘So, here’s the problem.’ Forrest opened the file on his desk and placed some gruesome crime scene photos in front of Quill and Lofthouse. ‘We have a car surrounded by witnesses for the whole time frame in which a murder could have been committed. We have CCTV footage of that car throughout. We have enormous coverage of the incident on Twitter, loads of social media photos. No one gets in, no one gets out. One of the two men in the car is brutally murdered. The other maintains he didn’t do it. Incredibly, we have some reason to believe his account – because we can’t find the weapon. The driver, Tunstall, has some of Spatley’s DNA on him, but only what you’d expect from him getting in the back to try and help Spatley after the attack, as he told us he did. I suspect,’ he finished, looking up from the photos, ‘this may well be how the word “impossible” popped up.’

Quill was making a determined effort not to smile; his target nominal had appeared on the horizon. There was something in the photos that was literally shining out at him, which Forrest and Lofthouse could not see. His team had, brilliantly, finally, a case of their own. ‘Is there any chance, sir,’ he said, ‘that my team could take a look at that CCTV footage?’

*   *   *

‘This lot can’t work out what we’re about,’ said Costain, as a young female detective constable closed the door of an office behind Quill’s team and left them to it. ‘We could be an elite squad, we might be irrelevant. I got halfway to convincing that young officer of the former.’

‘You didn’t say a word to her,’ said Ross, switching on a PC.

‘It was how I walked.’

‘Oh, I’d let myself forget that for just a second. You’re such a people person.’

Costain’s front remained intact. ‘One of us has to be. But, being serious, thank you for noting that.’

Ross didn’t make eye contact with him as she set up the PC to view the footage. That holier-than-thou carefulness that Costain often adopted these days in his fear of going to Hell seemed to annoy her more than it did Quill and Sefton.

When it appeared onscreen, Quill’s team moved in close to see the images that might give them new purpose. Only Lofthouse held back. They were looking down on a car caught in a traffic jam, protestors swarming around it, some of them looking up at the camera and covering their faces further. A couple of bricks were thrown towards it, but nothing hit it, thank God. Many of the protestors were done up in that Toff mask and cape.

Then something different came walking through the crowd, approaching the car from the left. Quill’s team all leaned forward at the same moment.