Stephanie Perkins is best known for her beloved YA romances, like Anna and the French Kiss. But with Perkins’ new novel, There’s Someone Inside Your House, the author ventures into very different territory—horror—in a novel that features plenty of gore and a voracious serial killer. It follows the story of Makani Young, the new girl at her high school, whose classmates are dropping like flies every time she turns around. While this shift to horror might surprise fans of Lola and the Boy Next Door and Isla and the Happily Ever After), Perkins told PW that anyone who really knows her won’t be surprised at all: she’s been an avid fan of all things horror since she was a teenager.

All of your books have centered around love and relationships. Can you talk about why you decided to make the shift to horror?

I always have to laugh at this question, because the answer is so obvious to me. To people who don’t know me, it looks like this colossal shift. But when the book was announced my friends and family nodded and said, “Yes, of course!” Horror has always been a big part of my life. Maybe that’s the wrong phrasing! I have a dark side and I love horror movies and true crime.

My house in general is really cheerful looking. All the rooms are painted different colors of the rainbow. It’s warm and fun. But if you look closer, you’ll see that the house is filled with various skeletal remains, like animal skulls. I kind of love that reaction when people are new to my house and they walk around, then lean in to look at something and jump back. Everything is warm and cheerful, but then there’s this little dark edge.

I kind of live on opposite ends of the spectrum. I really love the feel-good stories and the fairytales, but I also am really interested in the dark side of humanity. I’m really grateful that my editor, Julie Strauss-Gabel, wanted this book, and that she and everyone at Penguin let me take this chance. To me it didn’t feel like a chance, but I know to everyone else it does.

What was it like to go from happy romance to horror? Did you lose sleep from scaring yourself?

I definitely never lost sleep! Though I also definitely have more serial killer dreams now than I used to. The theme of them is always curiosity. The writerly side of me takes over in those dreams and wants to understand what’s going on and why.

But as far as the writing, it’s been public knowledge since 2012 that I was going to write a horror novel, so I’ve been talking about this book for several years at events, and I’ve also been telling people it’s not that different from my other novels.

I keep saying that There’s Someone Inside Your House is Anna and the French Kiss but with a body count. It still feels like my characters, my voice. It really is like taking any of my other book situations, then just adding a really bad thing on top of it.

I would never push someone to read a horror novel who doesn’t like horror. I used to be a librarian, and if someone told me “I don’t like fantasy,” I made it a personal mission to find one for them. Horror is different. I don’t know what a reader has been through in their past, so I don’t know what triggers they have. But if they are open to it, I would urge readers to try it. There are things to balance out the tension in my book, like a romance. Not to demean it, but I do feel like it’s horror light.

Do you have favorite horror movies or shows that influenced you?

Absolutely! I am interested in all genres of horror. Slashers are my favorite. I got interested in horror when I was a teenager in the 90s, at the height of films like Scream and I Know What You Did Last Summer. So those movies are the biggest influence on this book. A contemporary one I love is All the Boys Love Mandy Lane. It’s kind of a cult hit but it’s slowly getting a following. On television, American Horror Story is also great.

But most of my passion now is foreign horror. It’s darker, grosser, and more likely to be banned here. I like testing myself with those extremes. I have this theory that some people who are attracted to the horror genre are afraid of the world, and watching horror is a way to prepare for what scares us. This definitely merges with my fascination with true crime. I don’t see it as frightening, but as [a way of] gaining knowledge that makes me a little less afraid.

What inspires you to continue writing YA?

I was not a happy teenager. Those were really dark, hard years for me. I remember vividly what it’s like to be a struggling teenager. You’re so close to being an adult, yet so many things are still out of your control. I think it’s not uncommon actually, for authors who write about teenagers to be writing about a period that stuck with them. And maybe I still feel a bit like that person I was, and I’m still trying to talk to teenage Stephanie, and communicate with her in some way.

But then, at the end of high school, I met the person who would be my husband.

I had the hardest time of my life in high school. But the best thing that ever happened to me, happened in high school, too. I think that’s why the romance novels came first. I kept wanting to re-experience the best thing that ever happened to me.

There’s Someone Inside Your House by Stephanie Perkins. Dutton, $17.99 Sept. ISBN 978-0-525-42601-1