Two stories of the same theme and starting point, however with two different outcomes, due to a different sequence of events happening, leading to a butterfly effect..
For example:
Global Warming
Situation A - The story as we carry on as we are... [disaster]
Situation B - The story if we start to change our attitudes and apply more thought to the environment ...[?]
So.
A Book:
Situation A: Running on the left of each new page
Situation B: Running on the right of each new page
Two stories which start similar however end very different, you will be able to see the difference as time goes on.
However this method could be applied to lots of subjects
