The rockpile theory of plotting

When a character changes--the first time s/he does things differently--we want to witness it.  That's one reason we're reading.  Usually this change happens at the book's climax.

But that change has to make sense; it shouldn't come out of nowhere.  Even if we're not sure the character is really going to make this choice or take this action, we need to see the potential for the change. 

We don't just want to see the pebble drop that tips the scale.  We want to see the rocks pile up throughout the