Narrative questions are the drive that keeps us watching a movie-we want to know what will happen next. Causality, or causes and their effects, is the glue that weaves this world together. One event causes the next and so on. There are several types of causality. The first is physical causality. The Saw machine is an example of physical causality where one action leads to another based on physical forces. However, physical causality can become predictable because it runs just like a machine. What goes up will always come down, that is simply the way the physical world works. When we clearly know the rules like the law of gravity then we know what to expect and there are no surprises.