Novelists often get carried away with characters. Or maybe that should be, characters often carry away novelists. Either way, well-developed secondary characters can run away with a story if you let them. In one of my sample book maps, I showed how this can happen.
In my fictional fiction (sorry for going so meta on you here), the secondary character Cordelia suddenly gets a lot of attention in Chapters 5 through 8, with a big-city adventure that has nothing to do with the heroine, the hero, or the villain.
If we can in fact tie Cordelia’s storyline together with Antonia’s in a plausible way, then Cordelia has a subplot. But if that’s the case, the subplot should amplify or contrast what is happening in the main plot. Also, we’d want to see more alternation between Antonia’s main plot and Cordelia’s subplot. If you stray from your primary story line for too long, the reader’s attachment to the protagonist can break. This leads readers to stop reading.
So the book map can show you where you need to mix up your subplot with your main plot. In this case, we need to insert some Antonia chapters in between Cordelia’s chapters. It’s also possible to mix scenes within a chapter: alternating three scenes featuring Antonia with three scenes featuring Cordelia or someone else. Tolkien does this in The Return of the King when he switches back and forth between Frodo and Aragorn.
What if Your Story Isn’t a Sublot?
When a story line like Cordelia’s branches off on its own like a runaway freight train, and you cannot plausibly tie it back into the main plot line, you don’t have a subplot. You have a side story. The difference is that a subplot is integral to the overall story arc, and removing it will damage the narrative. Perhaps not irreparably, but it will take some doing to patch up the holes.
A side story, on the other hand, can be pulled out of the narrative without doing any significant damage to the surrounding scenes. It’s like the difference between remodeling and redecorating. You can take the curtains down without too much fuss, but if you rip out built-in bookshelves, you’ll have some work to do to mend the walls.
I have seen books make it to print with side stories intact, but these make for unsatisfying reading. The feeling of reading two unconnected stories at once is unsettling, especially when we’re accustomed to seeing such stories come together eventually.
If you find yourself with a side story, I recommend pulling it out and letting it stand on its own. There are several things you can do with such a story.
My favorite is to offer it as a free download for subscribers to your newsletter. If these subscribers have not read your book yet, the side story will give them a taste of your writing style and can help convince them to buy the book. If they have read your book, the side story gives them a chance to spend some more time with your setting and characters.
If you already have some other item serving as your sign-up premium, the side story can be offered as a feature on your web site. This is best for short stories, that is, under about 7,500 words or so.
If your side story is longer than that, consider publishing it as an e-book instead. Whether you choose to make it permafree or charge for it is entirely up to you. The longer the story is, the more likely you are going to be able to charge for it. Your ability to sell a short work will also depend on your track record as an author. Results vary widely, so it’s certainly work experimenting to see what kind of results you get either way.
You probably had fun writing the side story, so your readers will probably have fun reading it.