On February 24, Bloomsbury will release The Forgotten Sisters, the final installment of Shannon Hale’s Princess Academy trilogy, on the 10th anniversary of the publication of the series’ launch title, the Newbery Honor-winning Princess Academy. The Forgotten Sisters’ 150,000-copy first printing brings the series’ in-print tally to more than one million copies, and Hale will greet some of her legion fans on a six-city author tour that kicks off February 21. The versatile Salt Lake City author has 20 books to her credit since the 2003 publication of her debut novel, The Goose Girl, which launched the Books of Bayern series. Hale’s wide-ranging oeuvre includes three books for adults, among them Austenland, adapted as a 2013 Sony Pictures movie; YA series Ever After High, starring the children of classic fairy tale characters; sci-fi thriller Dangerous; fairy tale-inspired graphic novels Rapunzel’s Revenge and Calamity Jack, written with her husband, Dean Hale, and illustrated by Nathan Hale; and The Princess in Black, also written with Dean Hale and illustrated by LeUyen Pham, a chapter book about a royal superhero, just optioned by Universal Pictures. In her roles as both mother of four and writer, this Salt Lake City author is obviously a skilled multitasker: PW caught up with her while she monitored her four-year-old twin daughters’ indoor soccer class.

A full decade since Princess Academy first hit the bookshelves? Does that seem possible to you?

It’s very exciting – but the time really passed quickly! In fact, I now meet women with college degrees and babies in their arms, telling me that that they read Princess Academy when they were kids, and I think to myself, ‘Wait! Didn’t I just write that? How is that possible?’ It’s a bit like watching my own kids grow up – it’s beautiful, but at the same time unnerving and surreal.

Can you recall the creative spark that ignited Princess Academy?

I remember I was writing The Goose Girl at the time, and one night my husband began telling me about a book he was reading, featuring a character who was tutor to a princess, and that’s where it first began. I started thinking, ‘What would it be like if there were other princesses in training as well?’ I wasn’t sure what I wanted the story to be, or how to complicate that idea further, but that got me thinking. As I began writing Princess Academy, the voice of the story took me in a different direction than my initial concept – the book took on its own life.

Did you know when you were writing that novel that it would spawn additional books about princess-in-training Miri?

I only think of one book at a time. I really don’t think my brain is capable of thinking in terms of one huge story arc – I have to split it up. As a reader as well as a writer, I feel like each book should be its own story. When I’m writing a novel, I visualize the character in terms of what has happened before and what happens after, and then must decide which part of the character’s life makes the most interesting story. I loved the characters and the world of Princess Academy, and decided I would go back to it.

Did the novel’s garnering a Newbery Honor at all affect your decision to follow Miri’s story further?

When that happened, Princess Academy received so much more attention, love, and readership than I could ever have imagined. I became a bit shy with it, and felt it didn’t belong to me anymore. I got letters from readers telling me that I had to write another book about Miri – and telling me what should happen next! Some of their ideas were exactly what I’d been thinking. When a book becomes beloved in a way that it becomes bigger than you, it’s hard to know how to follow it up.

So the Newbery accolade was a bit intimidating?

Actually, it was both validating and hugely intimidating, and it continues to be, even 10 years later. It is the most significant thing that has happened to my career. When people ask me what it was like getting that call with the news, I still break down crying – it was a beautiful and loving thing to happen. I was able to deal with the pressure that came with it by compartmentalizing it rather than carry it on to other books. But it did take me seven years to write Palace of Stone, the second Princess Academy story.

In The Forgotten Sisters, Miri moves on from student to teacher when she is ordered to travel to a distant swamp and start her own princess school for three cousins of the royal family. What inspired that twist of plot?

In the first book, Miri and the other characters live on Mount Eskel, a part of the kingdom that is generally viewed as not as valued or important as the city or farmlands. I mention one other territory that is even worse off – the remote swamp. I always wondered what life in the swamp was like, and knew I wanted to visit there. And I felt that there were unanswered questions about these three girls who are relatives of the king, and I wanted to unravel the secret behind their lives.

Any chance you might reconsider ending the series here, and add a fourth installment to Princess Academy?

I feel like Miri’s story is complete, and in a way it would be almost too hard to suspend my disbelief and make something else happen to her. I know where she’s going in the future – she has wonderful things in store, but I don’t think they will be the subject of a book. I have thought of telling one of the sister’s [from The Forgotten Sisters] stories and have sketched it out, but we’ll see. My problem is that I have an embarrassment of ideas. There are so many books I want to write and so many characters whose stories I want to explore. Whenever I finish a book, I wrestle to discover who gets chosen next.

And who won that wrestling match most recently?

Right now I actually have more projects than usual going on. In the past, I’d normally work on two books at a time, and go back and forth between them. But at this point I’ve written first drafts of eight books – one’s a book of short stories, one is a screenplay, and the rest are novels.

That’s quite a lot to have on your drawing board at one time.

I didn’t initially work that way, but was forced to couple of years ago, when I started writing the Ever After High series. The turnaround time for those books was so fast. I recall saying to my husband, ‘I told them I could do this, but I have no reason to think that I can!’ I’m usually a slow writer and do a lot of revisions. But I did the Ever After High books really quickly, and was really happy with them. That experience opened a floodgate in my brain, and I began to think, ‘Maybe I can write all these books that I want to write after all.’ When I begin a book, I like to think deeply about only that story for a period of time, maybe a week or a month. And then I can begin to focus on other projects, too. I think I’m pretty good at multitasking.

And you’re obviously adept at juggling genres as well. Is it difficult for you to move in so many fictional directions?

I began writing when I was very young and went on to got my MFA in creative writing. When I wanted to tackle my first real novel, The Goose Girl, I decided to base it on a fairytale. I’ve always loved fairytales, and I decided if I was going to commit a couple of years of my life to one story, I wanted it to be a story that mattered to me. And I’ve continued to work that way – no matter what the theme of the book is. The more complicated the story, the more interesting it is for me to write it. And if it seems too hard to do, that makes it even more appealing to me. I do like trying different genres – though sometimes that feels a bit like a disease.

But not a bad one to have contracted?

I guess that’s true!

Princess Academy: The Forgotten Sisters by Shannon Hale. Bloomsbury, $17.99 Feb. ISBN 978-1-61963-485-5