‘They’re no use to us,’ snapped Oskar. ‘All the data in the world isn’t any use unless we can talk to base to get that airborne intel. You see?’

‘But they can still see where we are, using the drones, even if we can’t talk to them, right?’ I asked.

‘That’s still no—’ Oskar began.

‘I’ve got a better idea,’ Nadia said suddenly, and quickly pulled up by the side of the motorway, just past the exit sign for the off-ramp. ‘Oskar,’ she said, pushing open the door on her side and climbing out, ‘dig out the flares, will you?’

Oskar reached around into the rear compartment of the SUV, unzipping one of the numerous large canvas bags there. He rummaged around inside, then pulled out a flare pistol along with several flares of different colours. He pushed his door open and passed it all out to Nadia.

I got out as well, too full of nervous energy to sit in the car one moment longer than I had to. I stepped over to the rail at the side of the off-ramp and peered down at the conga line of former humanity snaking through distant streets. Even from a couple of kilometres distance, I could hear the massed shuffling of their feet.

I looked back, in the direction of the multi-storey car park. I could make out the distant echo of hundreds of crude tools hammering at its walls.

I turned back to see Nadia load a flare into the gun before aiming straight up and pulling the trigger. The flare shot high into the air, then exploded into a tiny white star, drifting in the wind before quickly fading.

‘Remember your training?’ Nadia asked, stepping back over to me.

‘A white flare means our comms are down, but we’re otherwise fine,’ I replied.

‘Very good.’ She nodded. ‘You were listening. Now all we have to do is wait and see if they send up an orange flare. If it’s orange, we turn around and head on home. White means we keep going.’

‘What do you think it’ll be?’ I asked.

‘White,’ she said immediately. ‘I don’t have any doubts about that, not unless something’s seriously wrong.’

She glanced to the south, and I followed her gaze to see a second white flare rise above the dark green foliage, on the far side of the wrecked bridge and the reservoir.

Oskar snarled something I couldn’t make out, and pulled his head back inside the car.

‘Onwards, gentlemen,’ said Nadia, and headed back to the SUV.

‘What about Casey and the rest?’ I asked, climbing back in. ‘We haven’t seen a flare from them, have we?’

‘Unless we missed it,’ said Nadia. Her shoulders rose and fell in a sigh. ‘Or maybe it’s just us who’ve got problems.’

NINE