‘Let me concentrate,’ Georgia commanded, knowing there was nothing she could do if someone was a good enough shot to blast the drone out of the sky.

Her mark to turn away from the building facades was a seven-storey car park, aiming towards a giant yellow pile-driving machine at the heart of the construction site. The video glitched as she crossed the threshold, throttling down to quieten the final approach.

Georgia eyed the podium, press and the seated rows of construction workers and their families. She saw the back of the prime minister’s head, with the City of London mayor and the French ambassador seated either side.

The signal stayed strong as Georgia flipped a switch on top of her control box to release the paint. The kick from the impeller sent the drone and cameras spinning.

Georgia’s view was blurred by a mist of paint on the camera lens, but she could see movement down by the stage.

Zac watched the view from one of the high-resolution cameras on the laptop.

‘Dead on target,’ he shouted happily.

Rather than bring the drone back, Georgia had programmed a hold. This would leave it hovering thirty metres over the site, recording events, until it was shot down, or the battery died.

As the drone rose, Georgia got a sense that people in the seats were scattering. Then her whole field of view flashed orange. Georgia lost video and the battery overheat light flashed.

‘I think they shot me down,’ Georgia blurted.

But the drone stabilised itself and the video came back. Smoke billowed and there were licks of flame.

‘Fireball,’ Gerard blurted.

The drone was stable. There was no more piloting necessary, so Georgia ripped off the FPV goggles.

‘Why’s it on fire?’ Zac shouted accusingly at Gerard.

‘How should I know?’

Georgia pushed between the guys to look on the laptop. Her FPV camera showed blurs, but one of the high-resolution cameras had survived and was showing the aftermath of an explosion.

Police were approaching the stage, wary of the grey smoke. The press were breaking out of their enclosure to get closer, while the audience of site workers grabbed kids and scrambled for the exit.

Georgia felt a chill as her phone started to vibrate. She saw Wendy’s name but ignored the call.

‘You total psycho,’ Zac roared at Gerard. ‘Spraying paint is minor assault, maximum two years. Setting off a bomb is thirty …’

‘It was paint,’ Gerard insisted, intimidated by Zac’s looming bulk.

‘You showed that video at the Red Parrot,’ Zac accused. ‘Fuel air weapon.’

Georgia was mystified. She’d been alongside Gerard when he’d set up the impeller the night before. The red paint looked like the same stuff they’d tested a week earlier and she didn’t see how Gerard could have turned the impeller from a paint sprayer to a bomb without installing something to spark the blast.