The best time to go to Walmart—and I do not believe this is up for debate—is 6:00am. By this (admittedly ungodly) hour, most of the stocking is finished, but few customers have arrived. You an walk the narrow aisles without having to duck behind support posts to let that crazed grandma with the wobbly buggy pass. You don’t have to wait in line at the self-checkout. You go in, and you get out. Clean. Efficient. Nobody gets hurt.

This is the way stories begin, at least in my mind. A setting, a protagonist, a shopping list of acts and scenes. These early moments of narrative construction have a kind of peaceful clarity, just me and the main arc. I like the simplicity.

And it would be fine to leave it there, if the goal was simply to grab floss and duct tape and get the hell out. But the thing that makes early shopping a pleasure makes a story, well, boring.

Enter supporting characters.

It’s tempting to treat the supporting cast the way we do real people who are peripheral to our own story—to pass by them politely, or to cast them according to simple categories of friend or villain. But in both the real and the fictional world, these people come to life only when we understand that, while their stories may not be like ours, they are nevertheless complicated individuals who bring their history and personalities to bear on us in unique ways.

I thought about this several times as I wrote the scene of Little Whit in the principal’s office. For starters, school employees are among the most influential people in a child’s life, but also among the most mysterious. It wouldn’t take much to view Dr. VerHagen as detached or Mrs. Welkie as a curmudgeon, and to leave them in that two-dimensional space. Yet without their caring and attention, Whit would have become another statistic, labeled a dummy or a troublemaker when the real problem was that he couldn’t see.

Not incidentally, this is analogous to a real instance from my own childhood. Although the people involved were much different, the fact is that I would never have gotten very far if it weren’t for a set of mysterious adults who recognized that my problem wasn’t emotional imbalance, but the inability to see. Once I got my first set of glasses, the world opened up, just as it did for Whit.

Of course, these characters can unravel the narrative just as easily as they enable it. Once an author recognizes supporting characters as individuals in their own right, they at once start causing problems. You can’t trust them to behave, and when they get out of line, they can screw up the narrative. Although she doesn’t get a lot of stage time in Junius, Bethany Whitman Farris caused me to do more than one rewrite before all was said and done. But without her complicated humanity, Whit’s story would have been significantly less interesting, and the novel would have suffered.

Even if you don’t want a crowd of people muddying up the story, you need the occasional crazy grandma to make you duck behind the end cap. Introducing a truly interesting supporting cast is not terribly efficient, but it makes for a far more interesting story.