We have a stray cat in our neighborhood, a big gray-and-white cat who shows up on our patio from time to time. He used to rely on a now-moved-away family for food and shelter. The kids in that family named the cat Timmy, and Timmy he’s been in what’s become their nearly year-long absence. Cathy and I have water out for the birds, and Timmy sometimes comes by for a drink. He also snacks on the dry cat food we leave for him. We even went as far as buying a heated shelter for Timmy, but I’m not sure he’s ever used it.

After the first of the year, we had a severe cold spell that we’re just now putting behind us. We hadn’t seen Timmy for three weeks or so, and, of course, we worried about him. I couldn’t stop myself from imagining him frozen to death in the bitter cold.

Then one day, there he was, sauntering across our backyard and up onto our patio. The dry food in his pan had gone soggy from the recent snow and rain, so Cathy gave him a fresh serving. When she opened the back door, he ran to our landscaping like he’s always done. He waited for Cathy to come back into the house. Then he came to the food, and he ate a good long while. Our cat, Stanley, sat at our back door and watched him through the nearly floor-length glass. At some point, I saw Timmy making his way into our next-door neighbors’ yard, and from there over to the house behind theirs.

It’s hard for me to explain how connected I’ve become to Timmy. He won’t let anyone near him. He comes and goes as he pleases. Some might say he’s quite the moocher, but there’s something about his face I can’t resist. If he comes to our patio, and there’s no food out for him, he sits patiently. If we see him there and are slow to respond, he moves closer to our door, still with that unperturbed look on his face as if he knows eventually we’ll feed him. Of course, we always do.

His absence these past few weeks, and now his return, have reinforced something I know about narrative structure. We must use the characters who walk onto our pages. Oh, sure, there are often ancillary characters who are there to fulfill a particular function even though they don’t figure into the heart of the work, but for the most part, in an early draft, we’re looking for those characters who will really count. How are they essential to the narrative arc? How will we miss them if they disappear, never to return?

There are some wonderfully colorful minor characters in The Great Gatsby who only appear once. The old man who sells the puppy to Tom Buchannan comes to mind. We see him once, but that puppy becomes important to the plot of the book. The major characters all have their own narrative arcs—Nick, Gatsby, Daisy, Tom, Jordan, Myrtle Wilson. We see them in the beginning and in the middle, and they all have something to contribute to the novel’s end.

Sometimes writing the draft of a novel is a matter of auditioning characters. They come onto our pages, and we have to decide who to keep and who to let go. If a character’s contribution isn’t immediately clear, we can give some thought to how we might be able to put them to use. Sometimes they can create plot. At other times, they can provide the set-up for something crucial that will happen somewhere down the line. The important thing is not to forget them. If need be, let them come back into the draft a few more times, just like Timmy taking his time to find our patio, the look on his face saying, “You don’t know why you need me, but trust me, you do.”