For author Tehlor Kay Mejia, writing a new book starts with the quest to answer what she calls a “big what-if question.” In the case of her upcoming middle grade debut from Rick Riordan Presents, Paola Santiago and the River of Tears, the big question was: what if the ghost stories we were told as kids were true? From there, Mejia says, “came the questions of what kind of girl would find out about this world, and what would she do once she did?”

The answer is Paola Santiago, the book’s skeptical, scientific 12-year-old protagonist, who dismisses her mother’s warnings about La Llorona, a tormented spirit from Mexican folklore with a penchant for stealing and drowning children. Mejia found her inspiration for Paolo close to home. “My daughter is a very literal, science-y girl,” Mejia says. “I’m a ghost story- teller and a tarot card reader and a person who lights candles and asks saints and ancestors for help.”

Mejia doesn’t remember when she first learned about La Llorona—aka the Weeping Woman and the Cryer—but she does remember being terrified of the legend from an early age. “Our ghost stories are presented as barely separate from the real world,” she says. “The way they’re told leaves so much opportunity for a child’s overactive imagination to fill in the blanks.”

Those overactive imaginations, Mejia says, make frightening stories powerfully appealing to young readers. “The world is a scary place when you’re small,” she says. “And as kids, we test the boundaries of those fears relentlessly to find out what kind of people we are. Are we brave? Reckless? Cunning? Resourceful? The way we respond to fear is such a good measure of who we are, so in a way I think scary stories help us discover our strengths.”

While Paola discovers her strengths and learns that La Llorona might be real, she never abandons her love for science—instead, she becomes more open to different possibilities. That’s something Mejia strongly relates to. “The interesting thing about writing Pao was how much of myself I found in her,” she says. “Mostly in her evolution from this black-and-white seeing girl to a girl that’s capable of forgiving herself and seeing things from another perspective, but also as a girl who takes the imperfect circumstances of her life and finds a way to use them to make things better.”

In addition to its exploration of science and the supernatural, Paola Santiago and the River of Tears is an #OwnVoices story that addresses race and class conflicts in the fictionalized town of Silver Springs. “This shows the most in Pao’s interactions with the police, who have unfairly dehumanized the Latinx population of the town,” Mejia says. “And in the way Pao’s friends and neighbors are victims of our country’s horrifying immigration policy.” In highlighting the stark income inequality in Pao’s community, Mejia drew from her own childhood experiences. “I was so aware of these divides from such an early age,” Mejia says. “I wanted to write a book that showed kids who were forced into awareness of their caretakers’ financial stressors early that they weren’t alone, because I so often felt isolated under the burden of that knowledge when I was young.”

Mejia couldn’t have been happier when Paola Santiago and the River of Tears found a home at Rick Riordan Presents, an imprint of Disney Publishing Worldwide that publishes #OwnVoices stories that integrate world folklore and mythology. “The idea that Rick and Disney wanted to carve out a space for marginalized kids to feel at home in those types of adventures was so incredible to me,” Mejia says.

Paola Santiago and the River of Tears also marks a milestone for Rick Riordan Presents. While the imprint has published books featuring a menagerie of fantastical creatures, Mejia’s novel is its first ghost story. And while Riordan may not have grown up with all the mythological characters now published under his imprint, La Llorona was a clear exception. He knew that story all too well. “When I was a kid growing up in Texas, I was terrified of going into deep water,” he says. “That wasn’t just because the movie Jaws had freaked me out.” Riordan even reports hearing ghostly wailing—and finding mysterious tracks in the mud—while camping near a river as a kid. “Paola Santiago is a lot braver than I was at her age,” Riordan says.