Two-time Newbery Medalist Erin Entrada Kelly ventures into new territory with The Last Resort (Scholastic, September 2), the first in a cross-platform mystery series that combines traditional storytelling with interactive technology. The novel follows 11-year-old Lila as she encounters ghosts at her late grandfather’s Victorian inn, where she, her brother, and their new neighbor team up to solve the mystery of her grandfather’s death. QR codes embedded throughout the book, which is illustrated by Naomi Franquiz, let interested readers help resolve ghosts’ unfinished business. A second book in the series, written by Jasmine Warga, is due out in January.

On a Zoom call from a writing retreat in the Pocono Mountains of Pennsylvania, Kelly spoke about her lifelong love of thrillers, the importance of addressing family grief in middle-grade books, and the novelty of writing an extroverted protagonist. Our conversation has been edited for length and clarity.

What’s your favorite mystery or thriller?

Lately, I’ve really been into anthologies, especially thriller/horror anthologies. One of them is The Black Girl Survives in This One. I like We Only Come Out at Night, and I also love Our Shadows Have Claws. I definitely lean more toward thrillers and horror. More in the same space as me, I do love Mary Downing Hahn’s Wait Till Helen Comes and [books by] Lois Duncan.

What drew you to their books?

It’s the writing and the storytelling. One of the things I find most interesting about mysteries and thrillers is you are writing toward an audience that reads a lot of this genre, and a lot has been done in this genre many times. Like, how many haunted house stories are there, right? So I love the challenge: How can I embrace the tropes of thrillers and mysteries, but also make something original that will hook readers? Mary Downing Hahn and Lois Duncan are good examples of that, because their books are so rich and textured. The anticipation is there on the page—just all the elements you want in a good spooky story.

The Last Resort is a new series starter. What makes it unique?

When readers encounter a ghost on the page, they have the option to scan a QR code, and the ghost will rise from the pages of the book. Readers have to help the ghosts figure out how they died and also what they need to cross over. There’s a mystery, a puzzle-solving element for readers who enjoy that, but you don’t have to if it’s not your thing. One of the fun challenges of writing this book was introducing ghosts that readers might be interested in interacting with and solving their deaths, while also honoring the readers who don’t care about the gameplay element and just want to read the book.

I really appreciate that the siblings in the book are collaborative instead of adversarial. Why did you include the little brother, Caleb, in Lila’s mystery-solving gang?

There are a lot of only children in middle grade—and I’ve written only children, too—because once you introduce a sibling, that changes the dynamic of the house, and it just changes everything. But most kids have siblings, so Caleb is there to fulfill that role of the annoying little brother. But I also wanted this to be a story about family coming together. I tell my students in MFA programs that your secondary characters’ main function is to provide dimension for the main character. Caleb does that for Lila.

The book is about ghosts and a haunted house, but also about grief, loneliness, and insecurity. Why is it important to expose middle-grade readers to these topics?

The first, obvious answer is that children experience those things, so books like this can help them work through it. But the less obvious answer is, for young people who have not experienced those things, books allow readers to live in an uncomfortable place where they might be sad or they might be scared or they might be lonely, but it’s a safe space, so they don’t have to actually have a parent die. They can experience, empathize, and understand what it’s like without having to actually experience it. When they do experience grief and loss, they’ll have some context for it. What better space to experience uncomfortable emotions than in the pages of a book, where it’s safe? That’s why people love horror and thriller books and movies in the first place. Being afraid is, in a weird way, an energizing emotion that makes you feel alive. But I’m actually not running from a serial killer. I can leave the theater and go home. But I get to experience all the emotions of living.

Mystery novels often invite rereading. What do you hope readers notice while rereading The Last Resort?

One thing that’s so fun about reading books like this is that, once you’ve read the book and know how it ends, when you reread it, you can see how the narrative is leading you to that ending. It’s especially true for books like this, where there’s something to be solved, and then when you go back, you have the benefit of knowing what’s going on, and then you can see how the author manipulated—for lack of a better word—the storytelling to make that happen. The sentence that you read in a certain way the first time around all of a sudden reads very differently when you read it the second time, with the benefit of knowing the ending—which is really cool.

What’s the difference between a good mystery/thriller for an adult versus one for a middle-grade reader?

I don’t think there is a difference. I think that the structure is the same. You still need great characters. You still need a great storyline. I would say the only difference is content. Obviously, you want the content to be suitable for a younger reader, but other than that, the scaffolding is all the same. It’s all about characters that readers care about and want to root for, or, if they don’t care about them, they’re intrigued by them, and [they have] an intriguing story. Mysteries and thrillers for young people and adults also have the same tension, conflict, suspense. All the ingredients are the same.

I loved Lila, and I also really felt like she was universal. Why did you choose to make Lila a girl who’s often told she’s “too much”?

A lot of my previous books deal with the inverse, where [the characters] are quiet and kind of meek and trying to find their voice. I thought, You know what? I want to do the total opposite. I want to do a character who does take up space. But guess what? That’s not right, either, because when you’re young, and especially when you’re a girl, everything you do seems to be not the right way to do it, and everyone else seems like they’re doing it well. But no one knows what they’re doing! So I wanted to celebrate a girl who takes up space and who learns that she can take up space. Even if you weren’t the dramatic overreacting kid, we all know what it’s like to feel like we’re not doing it right, especially at that age. That feeling is universal across ages and personality types.

Sandie Angulo Chen is a writer and bookseller in Silver Spring, Maryland.