At first I heard only the sigh of the wind, and the rustle of branches. Then it came to me – a far-off yipping that aroused a primal fear in me. A pack of dogs.

‘We should turn back,’ said Alice. ‘We’ve still got miles to go, and we don’t know how many there might be.’

‘Let me think,’ I snapped. ‘We can’t turn back.’

‘For God’s sake, Jerry – the last thing we want to do is get attacked by wild animals just when we might have a chance of rescue. We need to turn back!’

I stared towards the nearest houses, still a good fifteen minutes away on foot, then back the way we had come. I knew from experience how dangerous even a moment’s hesitation could be, but a succession of days that were identical to each other had made me slow.

I pulled my shotgun from my shoulder and patted the pocket of my jacket where I always kept spare ammunition. ‘We’re not turning back,’ I said. ‘I’ve dealt with worse before. Now come on.’

One of the things I remember the most from those first months alone in the world is the sound of dogs crying out day and night. Most of them were still locked in their homes with their dead owners – unlucky for them, lucky for me. As for the rest, they wandered the streets in search of food and – once they ran out of corpses to feast on – prey.

I started to move again, ignoring the pain in my lungs and chest. I was close enough now to the houses of Wembury to see their empty windows and the cars scattered across the road. The church spire rose above the rooftops, like a beacon drawing me towards my cache of supplies.

I heard barking from somewhere behind me and knew the dogs were on my trail. I tightened my grip on the shotgun, despite the sudden dampness of my palms, and turned to see a heavyset canine that looked as if its mother had mated with a bear come barrelling towards me, low and squat with legs pumping furiously. Its jaws gaped wide, its eyes white around their edges. I came to a stop and had to fire twice before the dog finally tumbled to the ground and lay still.

I cracked the shotgun open and hurriedly fumbled two more cartridges into the barrel before snapping it shut again. There was no point in running any more; even if I tried, the rest of the pack would catch me long before I reached the nearest of the houses. The best I could do was take a stand and hope for the best.