Very little about 19-year-old Stefan Bachmann says “typical teenager.” Born in Colorado, he moved to Switzerland with his family at a very early age and is a dual U.S.-Swiss citizen. His mother homeschooled him until he enrolled in the Zurich Conservatory in 2004 at the age of 11.

In addition to his passion for music, Bachmann says, he’s also always been a writer. After producing several trunk novels that he describes as “awful,” he began writing The Peculiar (Greenwillow) at age 16. “The first spark came from me wanting to write a book with all of the things I liked in it—war and steampunk and Victorian stuff,” he says. “I couldn’t find the book in a bookstore so I thought I should try to write it myself.” Though Bachmann says he understands why people emphasize his youth, the focus on it is not an entirely positive thing: “I guess it’s good for marketing, but it’s not something that I’m super happy about, because I hope the book can survive on its own.”

Bachmann sent out query letters for a year, “one at a time, which is not a good idea.” Then he got a response from Sara Megibow at Nelson Literary Agency and signed with her in fall 2011. Virginia Duncan at Greenwillow bought The Peculiar a week later in a two-book deal. “I don’t have any other editors to compare her with, but she’s great,” Bachmann says. “She’s really exact and she always knows what the book needs to make it better.”

The Peculiar had a first printing of 100,000 copies and met with critical acclaim; it was also a #1 bestseller in Switzerland, and rights have been sold in seven languages. “They’ve got a media blitz thing going on here,” says Bachman of the fame he’s achieving in Europe. “[I’ve been doing] tons of interviews, so a lot of people are hearing about it now. I just had a TV thing yesterday. It was pretty scary, [but] it’s interesting to see how all this media stuff works.” Asked if he’s getting a swollen head, Stefan laughed and responded, “I hope not. That’s like the last thing I want.”

Bachmann’s levelheadedness is also reflected in the maturity of his story; he counts J.R.R. Tolkien among his influences. “The whole steampunk thing,” he adds, probably came from his childhood love of Disney movies like The Great Mouse Detective and Atlantis. Then there’s Susanna Clarke’s Jonathan Strange and Mr. Norrell: “That was definitely an influence,” he says. “I tried to make The Peculiar a kids’ version of it.” Despite his obviously high ambition, being compared to Dostoevsky and Dickens by the Los Angeles Times took Bachmann aback. “I’m a real Dostoevsky fan so that was probably the biggest compliment, though I think it’s a little bit crazy because he’s a master.”

Amid his literary success, Bachmann sees his music as being just as important as his writing, and he continues to study composition in Zurich. He’s managed to merge his two worlds—he wrote musical pieces for The Peculiar’s Web site and trailer—and sees parallels between the two. “I think the most basic one is that they both take practice,” he says. “You can start music at age five and at first you’ll be bad, obviously, and then you practice a while and you’ll get better. I think it’s the same with writing. If you practice writing a lot and read a lot, you’ll get better at it, though you have to have the spark to begin with.”

And Bachmann shows no sign of slowing down; he’s just turned in his second novel, The Whatnot, to his editor. “I was nervous because it’s the second book,” he says. “It’s the conclusion to The Peculiar, a duology, so it wraps up the story. The first book had a cliffhanger, and that probably annoyed people.” Bachmann’s next book will “switch between contemporary and historical, which is going to be really new for me, but I can’t really say a lot about it yet. [And] when I’m 25 I’d like to write an adult book—when I’m actually an adult.”