Here are some nerdy writer's notes from a lecture of narrative progression by Lan Samantha Chang.

There is a readerly pleasure in watching a narrative unfold. It is the pleasure of reading and waiting--through detours and digressions--to a satisfying end.

Narrative progression needs APPARENT variations of speed, but ACTUAL consistency of forward momentum. Example: James' Portrait of a Lady. When Isabel Archer discovers (hundreds of pages into the book) something very bad about her husband (I won't give too much away) everything changes. The moment of discovery is followed by an apparent change of pace because an entire chapter is then devoted to Isabel sitting in a chair and thinking about the past. But the forward momentum is actually consistent because her character is learning new things and changing with each revelatory thought she has in that chair.

Readers need apparent variations in pace in order to mimic life, and to take them through the pleasures of joy, grief, hope, fear, relief. Narratives need consistency in forward movement to give it energy, internal tautness.

Lots more in that lecture that folks can buy on CD for $8 if they'd care to. Perhaps a group of us can chip in for a set of the strongest lectures, then pass them around.