When Greenwillow published Megan Whalen Turner’s debut novel, The Thief, in 1996, the author never imagined that other YA books set in the same fictional ancient world would follow – or that her fantasy adventure would be awarded a Newbery Honor. Yet she went on to wrote three additional novels centering on Eugenides the thief, whose destiny is entwined with the fates of three feuding nations: The Queen of Attolia (2000), The King of Attolia (2006), and A Conspiracy of Kings (2010). Turner will continue her saga in Thick as Thieves, due May 16 with a 100,000-copy first printing, whose title and cover are revealed here. To celebrate the 20th anniversary of The Thief, Greenwillow will release repackaged paperback editions of that novel and its three follow-ups next February, featuring new covers and additional content, including maps and character roundups. PW spoke with Turner about the genesis of her fantasy, what it was like to extend the story beyond The Thief, and her most recent and future revisits to her fictional universe.

Looking back more than two decades, what initially inspired the story of Eugenides, his allies and foes, and their world?

The idea for The Thief had been brewing in my mind for quite a while. Right at the very beginning, I was drawn to the idea of a person traveling in the company of other people who entirely underestimated him and failed to recognize who he was and what he was capable of doing. But the story didn’t get off the ground until I found the right setting. I knew I wanted a landscape that didn’t look like Middle Earth, but that would seem reasonably familiar to readers.

It took me quite a long time to figure out that a setting resembling Greece was the right choice. Thanks to the unit on ancient Greece that virtually every elementary school kid in the U.S. studies, I was pretty sure that most of my audience in this country would be able to imagine this landscape, with just a few important cues – and that it would fire their imaginations.

Did The Thief’s Newbery Honor take you by surprise – and was it that accolade that led you to continue the saga?

Things have changed so dramatically since the mid-1990s, when there wasn’t the same conversation and buzz online. I didn’t have a clue that I was even being considered for the Newbery. My husband and I had been joking that I might get that wonderful phone call, but I was still completely unprepared when it came – I wasn’t even sure what date the winners would be announced!

I wrote The Thief as a standalone book, yet I knew there was a tremendous amount more that I had to tell about the characters, others related to them, and their world. I had trimmed quite a bit from the first novel, since I assumed it was a one-off, and never thought I’d be following the characters and story further. But my editor, Susan Hirschman, called me right after I received the Newbery call, and she handed the phone to Barbara Barstow, then children’s librarian at Cuyahoga County [Ohio] Public Library, who asked me when the sequel was coming out. That’s when I started thinking about where the story might go. And as I began writing The Queen of Attolia, I became more and more comfortable with the idea of further exploring this world, and realized that I did, in fact, have a number of stories still to tell in it – it is a tremendously fun place to play!

Why did you decide to pen Thick of Thieves, which will pub seven years after A Conspiracy of Kings, at this time, and was it a challenge to return to this ancient realm?

Well, that’s a bit embarrassing. It’s not as if decided to wait seven years – I just work that slowly sometimes. I actually started the fifth novel soon after I finished the fourth, so I never really left these characters and their world. They’ve always stayed with me. They float in my head – when I’m at home, when I’m at the grocery store – pretty much nonstop. I’ve never been separated from them.

And I’m so grateful to my editors, first Susan and now Virginia Duncan, and everyone at Greenwillow, for their incredible support and patience with my writing pace. When I began my second novel, they told me to deliver it whenever it is ready – and that I should take as much time as I needed to make it the book I wanted it to be. I can’t begin to say how gratified I am to have that ongoing support, and how very lucky I feel.

And as you mark The Thief’s 20th anniversary, might you consider expanding the Queen’s Thief saga beyond five installments?

The truth is, I only realized that it has been 20 years since The Thief came out when someone pointed that out to me not long ago. I am so pleased to be still here writing, and to know that people are still reading my books – and new readers every year. And for the growth of my and other authors’ fan base, even worldwide, I have to point to the Internet. It makes me so happy to see readers pass on recommendations for books – new ones and classics – on Twitter and blogs.

And I have already begun writing the sixth Queen’s Thief novel – I tell people who ask, “Yes, Mom, I have started my homework!” I hope this book won’t take me seven years to write, but a long time ago I promised myself that I would not engage in teasers – that’s not a nice thing to do to readers if they might be looking at a number of years before the novel comes out. I also refuse to answer readers’ questions about what I’ve meant by this or that in my books – my go-to response is, “I’m not telling.” I love to see people talking about my books online, interpreting scenes and sharing little things they’ve noticed. If I answered their questions, I’d short-circuit that conversation, which is something I never want to do.

Thick as Thieves by Megan Whalen Turner. Greenwillow, $17.99 May 2017 ISBN 978-0-06-256824-3