That's where the good plot and character development takes place. In the case of fanfiction, you don't really have to develop the characters since they already come pre-packaged for you, but it does help to figure out their motives and plans during the quiet bits.

I believe there's a hero in all of us that keeps us honest, gives us strength, makes us noble, and finally allows us to die with pride, even though sometimes we have to be steady and give up the thing we want the most. Even our dreams. -- Aunt May, Spider-Man 2