This style is a bit more tricky, but provides a really cool experience for the reader. Basically, you take a storyline --- let's say, of a college kid going to the grocery store to pick up his weekly ration of food. As the story progresses, at various points in the narrative, other stories are linked to, and once read, when the reader comes back to the main narrative, 'it has changed'. It can get pretty complicated, so I drew out a simple map if my explanation wasn't forthcoming enough. Have fun with this. That's all it's meant to be.