Two middle school girls are driven to murder by the Kingman, their favorite creepypasta character, in Starck’s Monsters We Have Made (Vintage, Mar.).

This is a story about stories. What led to this focus?

I think stories—especially those we encounter as kids—shape us. In so many facets of our lives, in our relationships, in our marriages, with our children, with our jobs, we’re telling ourselves stories and trying to make sense of the world. And what happens when some of those stories take a turn? One of the more obvious, real-world links to my novel is Slender Man and the stabbing that happened in Wisconsin 10 years ago. But the seed of the novel was actually planted much earlier, when I was in middle school and I read Susan Cooper’s The Boggart. It’s about an ancient creature that, through the computer, gets brought into the world and that collision between old magic and new technology. That story stayed with me and I wanted to explore some of those themes.

What inspired the Kingman?

Well, the Slender Man stabbings were what began to raise the questions for me: What happens when we act on a fiction, when we make it real in the world? Can a crime committed in the name of a fiction be a sort of fiction as well? What does that mean? So definitely Slender Man. Definitely the Boggart. The dark fairy tales of Angela Carter. I was a big Buffy fan, so some of those monsters. In an early version of the novel the Kingman was also based on a mythical creature called the Erl-King, who came from multiple sources. In that story, a father is riding on a horse with his child through the forest. His child says, “Oh look, father, I see eyes in the woods,” and the father says, “No, that’s just lights on the trees,” and the son says, “Oh, I see this other kind of monster,” and the father says, “No, it’s just this.” He’s always trying to rationalize away what his son sees and by the end of the ride, his son has died on the horse in front of him. So, very dark. Oh, sorry, and one more: Frankenstein—especially this idea of what do we create and what do we do? The imagination is such an amazing, powerful thing. What do we do with what emerges from it?

The novel also wrestles with the complexities of parenthood.

I think that comes from my own anxieties surrounding parenthood. I am not yet a parent, but it’s something I’m thinking about. What are the risks of having of a child? What are the risks of loving that much and that hard forever? It’s such a strong bond and you sacrifice so much for your children. I see my friends who are parents and my own bonds with my parents and the weight of that love is so powerful. What do you do with that love when the person you’ve projected it onto does something terrible? What is the responsibility of a parent’s love for a child?