In Under the September Sky, the main character, Sapphire, is terrified to ride the carnival amusement known as the Ring of Fire or Super Loop. She writes stories about it, and one of her characters, Elsie, is also haunted by the ride but not in the same way as Sapphire. Here's the explanation I wrote in the back of the book:

A version of Elsie’s story also appears in my collection of poetry and short stories, The Forsaken. I wrote “Elsie” nearly a decade ago as an experimental flash-fiction piece. I’ve wanted to go back to Elsie for a long time, discover who she was and why she never ended up with the boy in the backward hat.

As I began plotting Under the September Sky, I realized that this story wasn’t about Elsie at all, but about another girl who was haunted by an urban legend. That story is one-hundred-percent fictional, although urban legends persist in small towns and likely big cities, too—as we learn from Washington Irving in “The Legend of Sleepy Hollow” (1820):

Obsessed as I am with that tale, like Sapphire, I decided that I wanted to create my own legend that would haunt the little valley where this story is set and would travel along with the carnival in every place it visited. I chose the setting because I have always found the idea of traveling carnivals to be fascinating. For several days, they are the hub of energy and light and sound, and when they pack up and go, they leave behind places that seem quieter than they ever were before, and if you just stand still long enough, or listen hard enough, you might just be able to see beyond the thin veil of time and see yourself on the rides.

Maybe with the boy in the backward hat.

***

In 2016, I saw a Ring of Fire, or Super Loop, in a gravel parking lot in my hometown of Heber, Utah. By all accounts, it appeared abandoned. The loop wasn’t intact, and it sat on a trailer as if someone had tried to pack it up. I didn’t understand why it was in the middle of a gravel parking lot, partially put together. The carnival was never held in that location. So why had it been towed from the carnival grounds and then set partway up, or why had it been towed from the carnival grounds to the parking lot intact, where it likely fell apart on its trip?

Most of all, I wondered what stories it had to tell. I took several photographs of it, then went back to take additional pictures a couple of weeks later, but the Super Loop had disappeared.

It, too, was a carnival ghost.