Jessica Townsend wrote her first story—a fairy tale titled The Three Koalas—as a seven-year-old living on Australia’s Sunshine Coast. The process made her realize that books weren’t delivered by fairies but written by ordinary people, and it was then that she knew: “This is what I’m going to do, the rest of my life, in one way or another.”

That wish came true. A post–high school retail job at Steve and Terri Irwin’s Australia Zoo led to a gig writing copy for the zoo’s website and, later, editing its wildlife magazine. At 22, Townsend moved to London, where she earned a living writing copy for property and travel companies.

Townsend found time for fiction, too, but that work—at least initially—was relegated to drawers. “I had the problem that I think a lot of writers probably have,” she says. “I started writing stories that I thought I might eventually turn into a book, but would never finish them because I’d come up with some new idea.”

Then she began plotting a tale about a girl who moves in with her eccentric Aunt Morrigan. Townsend quickly recognized that Morrigan was a much more compelling character than her intended protagonist. “I started working backward from there,” she recalls. “How did she become this interesting woman? What happened in her childhood, and where did she come from?”

That interrogation proved the inspiration for Townsend’s debut novel, Nevermoor: The Trials of Morrigan Crow (Little, Brown, Oct.)—a middle grade fantasy about a cursed girl who is destined to die on her 11th birthday but is rescued by a mysterious man. He brings her to safety inside the magically protected city of Nevermoor; in order to remain there, she must win admission to an elite group called the Wundrous Society.

Nevermoor was the first project that Townsend was never tempted to abandon. “And that’s strange to me, because I’m a quitter,” she jokes. “I call it a kitchen-sink novel, because every shiny, new idea that I had, instead of giving up on this book and then starting something new, I would just be like, ‘Well, you know what? I’ll put it in Nevermoor.’ ”

Townsend chipped away at Nevermoor for a decade while working full-time as a copywriter before deciding that, if she wanted to finish, she’d have to make a change. “When you’re in that world of deadlines and you’re writing creatively for your job, it’s really hard to then go home and give yourself a deadline and make yourself write creatively on your own project,” she says. She returned to Australia, took a job selling insurance, and completed the manuscript.

She landed her agent—Gemma Cooper of the Bent Agency—after just one month and 11 queries. Townsend received three other offers of representation, but knew in her gut that Cooper was the right choice. “I feel like I’ve really been proven right,” Townsend says, “because she’s a brilliant, professional, bright woman, but she’s also a big part of my life emotionally, as well. And that’s what I wanted. I wanted an agent who would be an agent for my career, not just for this book.”

Cooper suggested some edits, which took Townsend about a year and a half to execute. On a Friday in October, Cooper submitted the manuscript to a select group of editors. By Monday, there was a list of people eager to speak with Townsend. Cooper ultimately sold the world English-language rights to Hachette, where editors including Helen Thomas and Alvina Ling helped Townsend tighten the story and strengthen its heart. Townsend is now hard at work on a sequel, which is tentatively scheduled for publication next fall.

Nevermoor is now an international bestseller that is being published in at least 27 countries and has been optioned by 20th Century Fox. When asked to name her favorite part of Nevermoor’s publication, though, Townsend doesn’t hesitate: “The fact that these brilliant people are working on my book. That, for me, has been the biggest thrill. I feel so, you know, hashtag blessed.” —Katrina Niidas Holm

Katrina Niidas Holm writes regularly for PW and lives in Portland, Maine.