Ask any two published romance authors how they plot their novels and you'll likely get two different answers. After all, some develop their plot as they write while others plot the entire novel before writing a single page. Either way, certain universal truths remain. Namely, to write a marketable romance novel, you'll need to come up with characters your readers will care about and a storyline that intrigues, along with great supporting subplots and secondary characters that will keep the readers turning pages, eager to find out what happens next.