It’s been a busy year for Adventures of Huckleberry Finn. There’s already been one novel retelling Mark Twain’s classic from an alternative point of view: Percival Everett’s acclaimed bestseller James. Now comes Adventures of Mary Jane (Delacorte, June 25). Hope Jahren’s young adult novel centers on a character who appears in only 30 pages of Huckleberry Finn but, in her brief arc, entrances Huck (“I hain’t ever seen her since, but I reckon I’ve thought of her a many and a many a million times,” Twain has him say).The scientist and author of Lab Girl and The Story of More grew up loving Twain’s classic, and her aim isn’t to reinvent that book—in a note, she writes that she hopes Twain would like hers as well—but rather to give literary life to a character who’s always made her curious.

Jahren, who spoke with Kirkus from her home in Oslo, Norway, says she kept all dialogue from Huck and Mary Jane’s interactions “just as Twain wrote it.” The task of creating Mary Jane’s story beyond the pages of Twain’s book led to a major research project. Jahren dug into the details of 1846 America during this “really fun” project, from Mississippi River steamboats to the food, clothing, and other details of daily life. Our conversation has been edited for length and clarity.

Do you remember the first time you read Huckleberry Finn?

What I remember most is when we [listened to it] as an audiobook in the car as a family. We were in Minnesota, and my son was about 8 or 9, and he just couldn’t get enough of it. It was one of those [times] where you get where you’re going and you just stay in the car to keep listening. I started to analyze: Why does he love this book so much? And I started to notice structural things about it—it moves so fast! The action is just incredible, one thing on top of another. And the old voice in the back of my head started to say, There aren’t really any interesting women characters. And yet the female characters, particularly the ones in Greenville, Mississippi, are so monumental to the plot. That’s when Huck first decides to be a moral person—that’s the first time he makes a moral choice for the sake of doing the right thing, as opposed to getting what he wants. 

There’s this set of chapters in which he’s interacting with Mary Jane and her cousins during their uncle’s funeral. And then he leaves them.

And he’s obviously fallen very deeply in love with this girl. But she doesn’t make sense as a character to me. You know, people are complicated. And she is just so simple—it’s almost like somebody putting on an act of being simple. It just didn’t make sense. So my first thought was to read and read and reread the dialogue between her and Huck a million times. And I thought, What if she was just as smart and resourceful and talented as all the girls I’ve ever known? All the real girls. 

At what point did you decide that you were going to fill her out, make her a character, and write a book about her? 

This might sound kind of goofy, but I honestly believe she’s a real person. I honestly believe that this is a girl and this is what happened to her. Once I figured out who she was, it was just a matter of writing it down. She’d been through so much. Huck thought that he was in it up to his ears, and she was, too, right? And I just felt like this person needed the dignity of being recognized for who she really was. And I hoped that a book could do that. 

How did you find that real girl and put her on the page? 

First, I got to know her by what she did say. And then I got to know her by what she didn’t say—what she was really saying when I read between the lines. And then it was just a matter of looking at her more carefully. What kind of shoes was she probably wearing? I got a book, and I learned all this great stuff—people, except for the very, very rich, didn’t have different pairs of shoes. I thought that by envisioning her world, learning everything I could about the ways things worked back then, that I would more fully be able to understand a girl like that. There’s really nothing made up about her. 

Was the book always aimed at young adult readers? 

I’ve always seen writing young adult fiction as the gold ring of authorship, in that these are the most precious readers we have. Young adults read with the intensity that you just never have again in your life. They’ll read and they won’t want to eat or sleep; they want to stay up and read this book. The characters in a book become the people in your life; they’re just as real to you as they are.

We talk about raising kids to have empathy. Empathy is realizing that everybody has their own story—all these people that you meet and you don’t know very well, they all have their own stories that are just as complex and important [as yours].

You talk about encounters that can build empathy; Mary Jane has lots of them on her travels. How did you create that landscape and set of people? 

I walked that path, Mary Jane’s route, many times. Huck falls in love with her, and she falls in love with Huck, and I wondered, Why? What do they have in common? If you read Huckleberry Finn, Huck has this incredible love affair with the river, and I thought they should have that in common. She should be able to relate to a lot of the stuff he was talking about.

When I was in college, I learned that Huckleberry Finn was the birth of American literature—that it was the first American “road” story. Then I read Vanessa Veselka’s work on why there aren’t any women’s road stories. I got really interested in [the idea of] what the girl’s story would be. This great piece of American literature has a boy who travels through time and space and comes of age and sees the world the way it is and makes his own decisions based on his own compass of what’s right and wrong. What does it look like for a girl to go that distance?

Even though Mary Jane is mostly an adventure story, it also has moments of social satire. There’s a pastor who talks about Mormons exactly as Trump talked about Mexicans, for instance. 

As I did the research, I started to get a broader view of the decades before the Civil War, which was a very similar time to right now in some ways. If you look at some of Andrew Jackson’s speeches and compare them to Trump’s, it’s uncanny. We like to think that the dramas we’re experiencing today are special, the product of this unique configuration of events. But some of them are much more the fundamental moral challenges that each generation is conscripted to interrogate.

Kate Tuttle is a writer and editor in New Jersey.