‘Look at this,’ said Kember. ‘You can’t swing a cat without hitting a police officer or a bodyguard. There’s no way anyone could get close to the president.’

‘Seguma has got plenty of enemies,’ Bowman reminded him. ‘Someone might slip through the net, even with all these guys about.’

Kember looked at him. ‘Weren’t you a cop once?’

‘Three years,’ said Bowman. ‘In the Met. Before I enlisted.’

‘You weren’t one of them tossers with a speed gun, were you?’

Bowman laughed. ‘Nah, mate. I never did traffic duty.’

‘What were you, then? Plod?’

‘I did two years as a constable. Then I went into specialist work.’

‘Doing what? Arresting climate change activists?’

Bowman shook his head. ‘Undercover operations. Infiltrating gangs. Drug traffickers, arms dealers, that sort of thing.’

Kember gave him a long look. ‘Where? London?’

‘Sometimes. But I worked all over the country. Liverpool, Birmingham, Manchester. Wherever they needed me. Sometimes I’d be undercover for months at a time.’

‘You make it almost sound dangerous.’

Bowman heaved his shoulders in a shrug. ‘There were less stressful ways to make a living. You had to have your wits about you all the time. One wrong move and your cover would be blown.’

‘You miss it?’

‘Not really,’ said Bowman. ‘I was a different person back then.’

‘Meaning?’

‘The police have a different priority to the army. They’re interested in putting the bad guys in handcuffs.’

‘And you ain’t?’

‘I want to kill bad guys,’ Bowman said. ‘That’s why I joined the Regiment, mate.’

The first weak shafts of sunlight were breaking through the clouds as they passed the Houses of Parliament. They took another left, turning on to Broad Sanctuary, and then Bowman saw the crowd.

A sprawling mass had gathered on Parliament Square, hemmed in by steel barriers, cheering and hollering. Dozens of police lined the side of the road, some dressed in black-hatted, white-gloved ceremonial uniform. Others wore less formal hi-vis jackets. Further to the west, a hundred metres away, a temporary stand had been erected for the world’s media. Camera crews jostled with reporters for space on the tiered benches, preparing for the arrival of the bride. No one was filming at the moment: the government had imposed a media blackout during the arrival of the VIPs.

Kember stayed bumper-close to the limo as it continued west on Broad Sanctuary. Bowman looked behind him and was surprised to see that the bodyguards in the sedan were still lagging several metres to the rear, making no attempt to close the gap to the rest of the column.