Before you write a chapter to your story/fanfiction you can work out what the pace is going to be like. 

 Is it going to start fast, slow or average? 

Is the middle going to speed up or slow down?

Is there going to be a really fast pace at the end or slow?

This might help with your chapters to make them more interesting to read,  if a story is the same pace the whole way through the reader will could get bored which is why bad or good things happen in a story; it adds extra interest to the story.