Navy blue jumpers and clip-on bow ties, gimlet-eyed nuns in starched white habits, the gravel playground where we jumped rope, May altars decked with lilacs, the catechism I can still recite by heart: my Catholic elementary school looms large in memory. What I remember most keenly is longing to be good. More than good—saintly. When I was eight or nine, the Vision Books of Saints were my favorite reading. Bernadette: Our Lady’s Little Servantand St. Therese and the Roses and The Cure of Ars: the Priest Who Out-Talked the Devil. These stories thrilled me. I vowed to be humble and obedient, but also brave and steadfast, as a saint.

Everyone I knew went to Catholic school. For us, public school kids were objects of fascination. They wore whatever they wanted and seemed loud and unruly. We heard rumors that they ate in a cafeteria rather than at their desks, had a gym where they were actually encouraged to run (a serious sin at our school), and went on something called “field trips.” We judged them barbaric and pitied their ignorance. None of them was ever going to make it into heaven, much less be canonized.

And yet, somehow, by the time I was in eighth grade, I yearned to be one of them. How did that happen? The usual suspect: reading. As I grew, my saints became more secular. The characters I loved best still inspired me to be brave and good, but they also made me strangely restless. I remember the day Sister Eugenia went around the room, asking each of us which high school we’d attend. When my turn came, to my own surprise I stammered the name of the public school. I was a star student, and Sister was horrified. She made me stand in front of the class and list my reasons for abandoning Catholic education. Who knows what I said? No way I could say what I was thinking: I want to see what it’s like out there.

Many, many years later, I began to write about Nella, a dreamy, inarticulate girl who became the main character in my middle grade novel Every Single Second. Like all the other kids in her working-class, ethnic neighborhood, Nella goes to St. Amphibalus School, and though she’s often restless, and asks questions without answers, this is the world she knows and loves. Life begins to change when she meets a girl who’s lived many other places, a girl who questions everything—even God. Things change some more when the diocese closes St. Amphibalus and Nella, who’s white, has to attend the mostly black public school. And everything changes, this time for good, when a boy Nella’s been close to all her life commits a murder that becomes national news.

I was scared to write this book. I’d never written about violence. While I often write about diversity in terms of economic class, I’d never dealt with issues of race. Writing for kids is always a huge privilege and responsibility, and with this book, I felt that more strongly than ever. The tragedy at the heart of the story doesn’t just come out of nowhere, and it was my job to understand where it does come from. I was afraid of offending someone or, far worse, of getting the story wrong. While working on the book, I did a school visit and someone asked what I was writing about now. As I described the plot, some kids flinched. One girl put her hands over her eyes. But others came up to me afterwards, asking how soon they could get the book. This was the same tangle of feelings I experienced all the while I worked. I didn’t want to think about these things. I had to think about these things.

Nella is a girl shaped by the powerful, well-meaning forces of family and tradition, just as I was. Questioning what she’s been taught isn’t just difficult. It feels wrong. Yet as she starts to perceive the walls that stand between her and others, her desire to look over those walls—even to knock them down—grows ever stronger. That feels right.

My old elementary school, like St. Amphibalus, is closed now, but I still remember every nun who taught me. My favorite of all, the model for Sister Rosa in Every Single Second, was Sister Diana Marie. Barely taller than I was, she radiated love and compassion, and I swam in her light. By now, my definition of “being good” has gotten much more complicated, but I have no doubt Sister Diana Marie was good through and through. In my book, I happily gave Sister Rosa/Diana Marie some of my favorite lines:

“Remember, Nella. We need one another almost as much as we need God. Why else do you think he made so many of us?”