‘Also, his van went missing in the west of London. That’s not far from Wembley. If he’s storing weapons there, it makes sense that the target is nearby.’

‘I’m not so sure, Sophie,’ said Tennant. ‘He’s also recruited from the University of Islington – these four men live within half a mile of Hackney where the Pride march is ending up. You could equally argue that his movements point to Pride. That’s where I’m going to focus most assets.’

Gabriel fumed inside. She was certain Tennant was wrong, but she didn’t want to challenge him in public a second time.

‘Do we warn the public? Do we allow these events to go ahead?’ said Bose.

That was the big question, thought Gabriel. It was now 7.45am. There was time to cancel all these events, to turn the football fans back at the mainland stations and airports, to disperse the LGBT protestors, to scrap the marathon. But that was one hell of a call. She looked to Tennant.

‘If we cancel all three events, we are telling the world London is closed,’ he said. ‘That’s a political call ultimately. And we are still working on assumptions here – that today is the day, that Abu Mujahid is in London. Given that, then I can’t see how we can realistically persuade them to cancel. But we remind the public about risk, that we ask for vigilance, and we get as many officers out there today as we can. And we focus resources on the Pride march.’

‘Well, this is it then,’ said Gabriel. ‘We have work to do. The clock is ticking.’

#

Bose had stopped at the coffee machine to grab some liquid breakfast when Gabriel caught up with her.

‘Listen, Eva, my neck is on the line here if this goes belly up. I need the CCTV to focus on cameras on the west side of the ANPR black hole.’

‘The side closest to Wembley, ma’am?’ said Bose.

‘That’s right.’ Gabriel said nothing more.

‘I thought the boss had gone with the Pride theory.’

Gabriel gave her a steely look. ‘He has. And that’s where uniform resources are being focused. But I want the CCTV search focused on the Wembley side of the black hole. Look, I trust my judgement on this. I’m not ruling out Pride, but we’d be mad to neglect Wembley. Okay?’

Bose nodded and left.

#

For the last two hours, Bose’s team had concentrated on ten major junctions between Hammersmith and Wembley. Hundreds more hours of footage had come in overnight from shops, petrol stations and security firms. The team of thirty-five had been working in long shifts, fourteen hours at a time, watching, rewatching, filing, recording, and they looked exhausted this morning.

‘Ma’am,’ said a young civilian woman who had just come on shift. ‘Think I’ve got something. It’s from a Network Rail 360 camera…’

Bose looked at the screen. The date stamp was 08.34, some thirty-three minutes after Abu Mujahid had entered the ANPR black hole. It was a frozen image, showing a grey van on a minor road in an industrial park next to a railway siding. The woman replayed the previous ten seconds. Bose felt a rush of euphoria.