In Maddalena and the Dark (Flatiron, June), Fine draws on the decadent culture of 18th-century Venice to explore a turbulent relationship between two teenage girls.

What appealed to you about 1717 Venice?

The Venetian government cared for poor and sick people through the ospedali system—these church orphanages created in the 1300s, which over the centuries became music schools because they had great composers leading the church orchestras. I was interested in the Ospedale della Pietà and knew Vivaldi had taught there. I wanted to include him as a character, and thought, “Where better than a Gothic Venetian music school to set a book?”

What surprised you as you learned more about the setting?

I didn’t realize when I began writing about Venice how many parallels I would find to contemporary America. Venice was in its prime during the Renaissance, but by 1717 it was in this post–Venetian Dream moment where the one percent was making decisions that were not in the long-term interest of Venice itself. It made me think about the political systems we have today and the ways people—myself, too—make choices that serve us in the moment but hurt future generations.

Tell me about the relationship between Maddalena and Luisa.

I was interested in those teenage female friendships where you love your friend so much that you sort of hate them, and it’s difficult to distinguish between “I love you” and “I’m in love with you.” When you’re socialized to think romantic relationships look a certain way, it’s hard to wonder, “Why do I want what I want? What do I do when it doesn’t come to fruition?” But seeing characters grappling with feelings that are fairly common but have been taboo—or have not been explored as fully in art—feels healthy to me, like a catharsis. Isn’t it better to think about these things in a fictional world so that when they come up in our real lives, we have the tools to handle them?

You’ve explored fairy tales in your previous work. Did any stories inspire this novel?

Definitely “The Little Mermaid.” In my research, I discovered that a girl could leave the Pietà if she wanted to, but she wouldn’t be allowed to play her instrument publicly ever again. That’s a difficult choice if you’ve been a musician since you were six years old. It’s that “Little Mermaid” question: do you want to go outside these walls and lose your voice, or stay where you are? In the original “Little Mermaid” story there’s a part toward the end where the prince is marrying somebody else, and the mermaid is given the option of killing him to get what she wants. She lets him live and turns into foam, but I was curious—what if she’d made the opposite choice and said, “I’m going to choose myself”? The combination of those two ideas led to the book.