“So far we’ve looked at two places where you can put the character emotion you’ve stripped out of your dialogue mechanics–into the dialogue itself and into the language of your descriptions written from an intimate point of view. A third place is interior monologue. Movies and television may be influencing writers to write more visually, using immediate scenes with specific points of view to put their stories across. But fiction can always accomplish something that visual media will never be able to touch.” From Self-Editing for Fiction Writers by Renni Browne and Dave King
In other words: The fiction writer moves in and out of a character’s mind the way a ghost moves through walls.