Through Line

Recently I was discussing writing mechanics with some other authors and the discussion turned to the through line concept, an item that I had not consciously considered, probably owing to my lack of formal writing education. The through line, they explained, is that concept/idea/view/attitude that pervades a piece of work and imparts the overall meaning to the tale.

"The plot?" I responded to gales of laughter (well, perhaps a snicker or two) before being corrected. It seems that the plot is the sequence of actions that tie the beginning to the end and allows the reader to navigate the story.  The plot is mediated by the through line, even if that line is never explicitly expressed.
When you bridge a chasm the first action is to cast a stringer line across.  This is the thread that allows the heavy cables, which support the girders, that allow the paving that forms the final bridge.  The through line is that stringer, a line that guides the cables of plot and supports the structure of scene, setting, and characters to trace the story.

You won't see the stringer in the final story, but it is there and as essential as all the other material.