Balance

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"The author makes a tacit deal with the reader. You hand them a backpack. You ask them to place certain things in it — to remember, to keep in mind — as they make their way up the hill. If you hand them a yellow Volkswagen and they have to haul this to the top of the mountain — to the end of the story — and they find that this Volkswagen has nothing whatsoever to do with your story, you're going to have a very irritated reader on your hands." ~ Frank Conroy

I've felt this way about writing ever since my first glimpse of the Leatherstocking Tales, in which Cooper describes every branch and rock in the forest. True, the story was written for people curious about the newly explored American frontier, but the over abundance of physical detail got in the way of the flow of the story.

The trick is to find a balance between physical detail and plot development in a way that paints a picture of the characters and setting without distracting readers from what's happening. This balance is especially tricky in mystery writing since necessary clues can be derived from physical detail. A good mystery writer will even throw in a few extra details, just to make the reader try to figure what is or is not a genuine clue. However, a mystery is first and foremost a story in which the action must flow in order to keep the reader engaged.