A squirrel fascinated by the cars and drivers zooming along the racetrack below his family’s nest stars in Revver the Speedway Squirrel, the debut middle-grade novel by the author of the bestselling Goodnight, Goodnight, Construction Site series and other picture books. Despite the odds, the curious and impulsive Revver is determined to realize his dream of joining the human speedway pit crew and feeling understood and appreciated—feats he finally pulls off with panache. PW spoke with Rinker about the challenges of stepping into a new format and the genesis of her distinctive middle-grade hero.

A squirrel obsessed with racecars is hardly a conventional middle-grade protagonist. What was your inspiration for the character of Revver?

My son, Zak, who is now 15, has always loved speed and things that go fast—especially race cars. My husband is the same way. If there is a car race on TV, it will be on at our house. One day, our family was watching a NASCAR race and a squirrel darted across the track to the infield. The commentator was laughing, and so were we, but that evening, when we were eating dinner, Zak asked, “Do you think that squirrel is going to be okay?” And I realized he obviously had sympathy for the squirrel, and I began mulling over the little guy’s back story and decided I wanted to explore it. I told my awesome agent, Lori Kilkelly, that I had been stewing about this idea. She is used to my offbeat ideas, and said she thought it would make a darling picture book. And when I told her I’d like to develop this squirrel character further than I’d be able to do in a picture book and was thinking of writing a chapter book instead, she told me to go for it and give it a shot.

So how did Revver the Speedway Squirrel morph from a chapter book to a middle grade?

Well, I started the chapter book, and wrote and rewrote and rewrote again and began thinking that I should have taken Lori’s suggestion to make it a picture book. But then, when Lori submitted the project to Mary Kate Castellani at Bloomsbury, she had yet another idea. She mentioned that it is easy for a sole chapter book to get lost on bookstore shelves, where series have such a commanding presence, and asked if I’d consider turning Revver into a middle-grade novel—with a sequel. So I encountered another new challenge. I’d written a 5,000-word chapter book and was faced with the prospect of turning it into a 30,000-word novel. I was happy to have the chance to delve into Revver’s story in an even deeper way, but I had no idea where to begin.

How did you tackle the task?

I am super grateful that I was working with an amazing, patient editor, who was willing to walk me through the process of writing a middle grade for the first time. I’ve done a lot of difficult things in my life, including running marathons and rehabbing a building, but writing this novel ranks right up there in terms of being beyond my comfort level. There was a lot of backing and forthing with Mary Kate over a number of months, and quite a few re-dos. I was so nervous that I would make a fool of myself, and worried that reviewers would say, “She really needs to stick to picture books.” It was an arduous process, but a labor of love for sure, and ultimately very rewarding. In the end, I am incredibly happy that I committed to it.

Revver is passionate about learning the mechanics and techniques of car racing, but your novel encompasses other aspects of his personality as well, including his bond with his family and his friends and his awareness that everything in life is connected. How did the storyline expand in those directions—and what is next up for Revver?

My 19-year-old son, Ben, is a deep thinker, and is interested in connections. So Revver’s observation that everything is connected was very much inspired by him. When Ben was about five, my husband and I woke up one morning to discover that he had covered our dining room table with pieces of copy paper taped together and, pencil in hand, he showed us how he had started in the very middle with a picture of one thing, and his drawings expanded outward from there. He told us, very earnestly, that he had figured out something very exciting—and showed us how all his pictures were interconnected. So that piece of the novel is Ben, and Revver’s love of speed and technology come from my husband and Zak. Inspired as they were by my own life and experiences, how could Revver and his family not have a special place in my heart?

I don’t know yet exactly what happens next to Revver. I am now writing the first draft of the second book, which I hope will come out in roughly a year. I am three-fourths through it, but I still have no idea how it will end. And I cannot wait to find out!

Revver the Speedway Squirrel by Sherri Duskey Rinker, illus. by Alex Willan. Bloomsbury, $16.99 Oct.6 ISBN 978-1-5476-0361-9