The idea for Train I Ride (HarperCollins, Jan.) came to Paul Mosier while listening to “Mystery Train,” the 1953 song written by American blues legend Junior Parker and most famously recorded by Elvis Presley.

“I heard that lyric, ‘Train arrives, 16 coaches long,’ and I wondered, who is singing? Where is the train going?” Mosier recalled. “I rarely make any decisions about a story; I just start writing. But I knew right away that there was a girl on the train and that she was 12. Then I let her tell me her story.”

That girl turned out to be Rydr, a name she gave herself after a fellow passenger mistook the name on her “unaccompanied minor” tag—Rider—for her first name. Rydr is being shipped to a relative she doesn’t know, half a continent away, because there is no one else to take care of her. Driven by equal parts anger and spunk, she has good reasons to act out. Her mother, a junkie, is dead; the grandmother who took her in made sure Rydr knew she wasn’t welcome.

It’s the Amtrak staff and some passengers who give Rydr reason to hope she can ultimately create a different narrative for herself. Her fate turns when a Boy Scout gives her his copy of Allen Ginsberg’s Howl because she has only one picture book to read.

“I love that poem and felt like it was okay to include it because I went to see the Diary of a Wimpy Kid movie with my daughter and there’s a girl under the bleachers reading Howl,” Mosier says. “For Rydr, it’s an important moment because she can relate so much to what Ginsberg is expressing,” Mosier says.

Rydr boards her train in California; Mosier is a Westerner, too. He lives in the Coronado district of Phoenix, just a few blocks from the hospital where he was born 52 years ago. Following high school, he left to attend Radford University in Virginia, a college he chose mostly based on its “two girls for every guy” ratio. The first thing he learned was that he wasn’t where he thought he was. “I thought I was going to school in the east but it turned out I went to school in the South.”

The second thing was that southwestern Virginia “was a very forgiving place to try to drink yourself to death.” He spent his first morning in Virginia in the town jail. That first brush with public drunkenness did not scare him straight, but he is now a recovering alcoholic.

He took one creative writing class but dropped it. After five different majors in five years, he graduated with a degree in social science—an amalgam of history, political science, economics, psychology, and philosophy classes that is usually a precursor to a teaching career.

But Mosier did not want to teach; he wanted to write, which he did for years without a breakthrough. (He earns a living as a “green” investments counselor.) A slew of rejection letters led him to self-publish two novels: one a middle grade book titled Story Girl, the other for adults. The third time, he got lucky. He queried an agent, Wendy Schmalz, who agreed to represent him if he made a few changes to the manuscript. Two weeks after she sent it out on submission, two houses expressed interest. HarperCollins offered a preempt for two books with an option on his third.

Like many writers who don’t immediately find publishing success, Mosier has a large store of ideas. His next novel, Echo’s Sister (Jan. 2018), is narrated by the older sister of a girl fighting cancer, a story “very much informed” by his own family’s experience. Mosier has two daughters, Eleri, 13, and Harmony, eight. After more than a year of treatment, Harmony recently received what, hopefully, will be her last dose of chemotherapy. “She is the inspiration, and she is tough,” Mosier says. “I wouldn’t wish this on anyone but the community has lifted our family in so many ways that it’s been a strangely beautiful experience.”

There’s a third book written and ready to turn in, too. It’s been, Mosier says, an unbelievable two years since he first partnered with Schmalz and HarperCollins. “It’s an honor to connect to an audience of any size, but Train I Ride is the first book that more than a handful of people have read, ” he notes. “It’s been an amazing experience so far.”