You know what I wish I’d figured out earlier in my writing journey? The importance of through lines.
Take right now. I’m working on a revision of THE DEFIANT HEIR (Book 2 of Swords & Fire). I got about two-thirds done with a first draft, then realized I needed to go back and revise before I wrote the last third where everything comes together. Why? Because the Everything that needed to come together was pointing all over the place, like a pile of dropped sticks, rather than forming a bunch of lines converging inevitably toward the climax. And I had a whole section of the book that was kind of just sketched in, with caution tape strung around it saying “UNDER CONSTRUCTION.”
I didn’t have a clear through line.
A lot of definitions will describe the through line as a theme, idea, or goal that continues from the beginning to the end of a story. I personally find it more useful to think of the through line visually, as a pure structural element.
The scenes and events in a story are beads, and the through line is the thread that strings through them all to make a necklace. Without the through line, you just have a pile of beads. The through line is what makes it a story.
If your through line is working, every scene leads to the next in a natural progression of cause and effect. Your protagonist has a goal, and is driving the action toward that goal. The core conflict runs true at the heart of the story. There’s a clear emotional arc to the story, too, as well as a plot arc; everything bends toward the climax.
It’s all too easy to drop your through line. For instance, I know one way I often do it is when something unexpected happens to cause a plot turning point. That’s good! Yay surprises! But if now suddenly my characters are doing and feeling all new things that have nothing to do with everything they were doing and feeling before, it’s going to feel disjointed to the readers. Even if the new things are all exciting and cool, if we’ve dropped all the threads the readers were invested in and excited about, they may lose interest or feel lost. We need core elements of the story to continue, sticking with us through every zig and zag, propelling us through to the end.
Another common way to wind up with a dropped through line is when you have insufficient agency for your main character. They have to be the one threading that string through those beads. If they’re running around reacting to things that fate or the antagonist keeps throwing at them, without having driving goals of their own which they’re actively pursuing, there’s no clear thread to connect the events of the story and carry it forward…and the readers with it.
The through line gives the readers something to wonder about, to be excited about, to be emotionally invested in. It’s what keeps them turning pages to the end.
I don’t think you necessarily need to be able to define your through line in an explicit word or phrase or statement. Really, it’s a combination of things: core themes, your character’s emotional arc, the main plot arc, the central conflict, your character’s goal. It’s the heart AND the spine of the story.
But you should KNOW your through line. At a deep, instinctive level—and you should also be consciously aware of it. You should be able to trace its passage through your story.
In this particular revision, I realized I didn’t know my through line well enough. I had a bunch of events, and I saw how they lined up with cause and effect to create a story, but I needed to clarify my character’s motivation and goals and emotional arc to give those events life and purpose, and to bring them all together. Once I got a better understanding of my through line, suddenly all the pieces I’d been having trouble fleshing out or fully integrating came clear. A lot of the bits that were giving me trouble or that I didn’t have energy for suddenly seemed easy to tackle.
To map the path of your story, you need to know where it starts, and where it ends, and the lay of the land along the way. But just as much, you need to know who is walking that path, and why, and where they thought it was leading when they first set foot on it.
Your through line is Ariadne’s string, to guide your main character—and you, and your readers—through the Labyrinth. Lose it at your peril.