I was in a species of army, although completely unsure of what we were fighting. There was nothing unusual about this, as most people lived in a state of partial unknowing. There had been ways to deal with this via some form of technology-assisted information assimilation, but those systems were in steady downtime, and what fragmentary contact remained was only available to our superiors.
Our detail was almost entirely degraded; only myself and a partially decohered colleague remained. He no longer spoke, but he could still work, respond, fly (we were a plane-based team) which was, again, fairly normal. We could work long after our other aspects went away. However, the plane was not in current use. We had ended up in a Frankenstein team built of multiple other details, and our CO had only spotty understanding of how many of our pieces operated. None at all about the plane. Planes were exotic, cars were dominant, and he instantly mothballed the plane and parked it in a field, and sent us to the driving details, where of course we had to co-pilot as neither of us could drive.
A short time after that we lost all of our vehicles, which is how we ended up walking along the motorway.
Something had been done to the motorways that simultaneously made them faster and much more safe. Nothing crashed into anything any more. You could walk down the fast lane (we were walking down the fast lane) and nothing would ever hit you. You had the sense (and steady glimpses, distorted as if in a cinematic approximation of a drug trip) of large vehicles rushing by constantly. The troop carriers, lorries, tankers and land rovers (both civilian and ours) were busy keeping the business of the end of everything well supplied with food, equipment, people, tech. Everything was suffused with a haze and a golden glow like a summer dawn or a sodium foglight.
I realised that to the side, to our left and over the hill, was a small dirt track which lead to the field where our plane was parked. Thinking like this was unusual; most people thought of distance as lines and points, with unsignalled destinations inaccessible. But I had different training. I spoke to the CO and we left the road, marching across all four lanes, trying not to flinch as the traffic flashed by around us.
At the end of the road was a broken hangar, most of the far wall missing, and our plane visible beyond, silhouetted against the sky, covered in ivy, in perfect working order. It only needed two to fly it, but I asked among the others if anyone would come with us. "Will you come?" I asked a very old man (there was no discrimination of any kind in our army). "The end of the world in an ivied plane?" But he feared the sky. They all did. Nobody flew anywhere any more, apart from us, and I felt sure that none of them would choose to come.