A big component of writing fiction is the 'what if?'
I was driving home in peak hour traffic the other day, when the cars seemed to slow down to a crawl. I could see cars turning left or right into other lanes, as if a car had broken down up ahead. As I got closer I could see the problem. A man, with crazy long gray hair, with clothes that hung loose and dirty from his body, staggering down the middle of the road, flipping drivers the bird. He seemed a little angry.
We all drove carefully around him and I went on my way, but that writer's voice started up it's usual routine.
What was he doing there?
How did he get there?
And from there to the what if game.
What if he was a secret agent, just escaped from his captors, still staggering from their interrogation drugs?
What if he was being chased by someone and the safest place to be was in the middle of peak hour traffic?
What if it was an experiment to see what the drivers would do?
What if it was part of a movie shot in real life?
What if he had just been deposited back to Earth after being kidnapped by aliens?