Fascinating writing always seems to have a touch of evil lurking over it. There doesn't have to be a demon that breathes thoughts into your mind, but it can help. Part of what invests readers in a story is the ever-present potential that something horrible might happen to the characters they've grown to care about. It can also be a force that drives the writer to create. There's an excitement that comes with having control over your characters and their fate. It's like those cartoons where an angle sits on shoulder and the devil on the other, each trying to force your hand. Sometimes the angel wins, and sometimes the darkness does.