I was eating at a restaurant on top of a tall building (like the Space Needle, although it wasn't actually the space needle). Happily eating, when I thought I caught sight of an atomic blast reflected in one of the mirrors.
I panicked and ducked and people stared at me as if I was mad because, quite plainly, there was no mushroom cloud outside.
Except that just then one did go off. On the horizon we could plainly see a mushroom cloud blooming. Everyone was caught between feelings of "Aah! World War 3" and "Wow, I've never seen a mushroom cloud before".
Then one went off much closer and the restaurant was quite literally knocked off of the top of the building. My last thought as it tumbled towards the ground was "I'm going to die. I can't die, can I?" and the knowledge that I had no idea what happened next.
Everything was black. I couldn't see, feel or experience anything. I thought "Am I dead? Should I be able to think 'Am I dead?' if I am dead? How long will I be like this?"
And then I was sitting in the restaurant again and everything was normal. Except that I had a video camera in my hand and the knowledge that what I had to do was to record good things in the world, or it would be judged unworthy and destroyed.
So I left the restaurant and wandered, recording happy events. And every time my attention wandered to things that weren't happy I'd start catching reflections of mushroom clouds in windows around me and I'd hurriedly return to my task, trying to stave off the war for a little while longer.
And then I woke up, thinking "What the hell was that all about." I've never continued a dream beyond the "falling into the ground" stage. I've never dreamt about nuclear war. It all seems a little odd.