We chat with co-authors Rebecca Mix and Andrea Hannah about I Killed The King, which is the first book in a thrilling locked-room whodunnit YA fantasy duology.
Hi, Rebecca and Andrea! Can you tell our readers a bit about yourself?
Rebecca: Hello! I’m Rebecca Mix, New York times bestselling author of weird magical books, including The Ones We Burn, The Mossheart’s Promise duology, two graphic novels for Neopets, and my latest, I Killed The King! But if you follow me on socials, you probably just know me as that lady that really loves native plants, bugs, and the Detroit Lions.
Andrea: Hi! I’m the author of several novels for young adults, including International Thriller Award finalist Where Darkness Blooms. I’ve also created a tarot deck and spellbook for Marvel’s Agatha All Along, and written for Hasbro’s My Little Pony comics.
When did you first discover your love for writing and stories?
Rebecca: I was very reluctant reader until I joined a reading contest to spite my fourth grade nemesis, where I was tricked into being a bookworm for the rest of my life. I caught the writing bug in middle school, writing ridiculous Pokemon and Warrior Cats fanfiction with other anonymous users on the Neopets role play boards. Which sounds ridiculous, but it’s true!
Andrea: Oh gosh—I feel like most writers figure out they love storytelling pretty early. What I think varies between us is how long it takes to land on our chosen medium. I was a visual artist for many years before I got serious about writing in my mid-20s.
Your latest novel, I Killed the King, is out now! If you could only describe it in five words, what would they be?
Rebecca: Important, magical ball gets murderous!
Andrea: Murder, mayhem, and magical beasts.
What can readers expect?
Rebecca: King is a really fun genre-masher – one part Knives Out, one part Margaret Owen’s Little Thieves, all parts delightful chaos! My hope is that there’s something in there for everyone – and that, if you like thrilers and mysteries, but you’ve been intimidated by fantasy, this might be a good “gateway” book to dip your toe in the water!
Andrea: To be honest, there’s nothing like I Killed the King out there. It’s a web of dynamic characters, a ticking clock, and elements of a classic whodunnit—all dropped into a French-inspired fantasy setting. It’s a wild ride, that’s for sure.
Where did the inspiration for I Killed the King come from?
Rebecca: I’m in a few book clubs, and outside of being very fun, it’s incredibly valuable as a writer to sit and listen to readers bluntly pick apart a story or trope. You learn so much! A few years ago, one of my book clubs turned into a big discussion about locked-room thrillers as a whole — why they work, why they don’t, what they wish authors would write more of, what they wish authors would never write again –– and as I sat there listening, I wondered what would happen if magic was involved. And then, like a lightning strike, King was there!
Andrea: This was all Becca. She sent me a text about a locked-castle murder mystery idea early one morning and I was on board before I’d finished reading the pitch.
Were there any moments or characters you really enjoyed writing or exploring?
Rebecca: King has one my favorite villain-confession scenes to date! I also really, really love the climax. My extremely nerdy, niche pitch for Vibes of the Climax in this book is if you ever played Pokemon Diamond & Pearl, and you, too, were traumatized from battling Cynthia and knowing she was about to wipe the floor with you, but it was too late to back out, that’s the energy you can expect here.
Andrea: Before the book came out, we were tight-lipped about who wrote which characters. But now that it’s in the world, I’ve completely given myself away by yapping about Clove too much. I just love writing her. She was the problem child of our first few drafts; the other five characters had a very distinct reason for being at Castle Avendell, as well as motive, when the king is murdered. But Clove comes from a long lineage of beast tamers who cared for the royal menagerie—until her father was shunned and their property stolen. It took a while to figure out why she was there and what her motive could be. It was a fun challenge for me, as a writer. Then I got to add in all the details I love about her, including her dry humor, penchant for all things pink, and her pet unicorn.
Can you tell us a bit about your process in co-authoring I Killed the King?
Rebecca: It was a lot of fun speed-drafting in the beginning, and then revision required a lot of organization. I swear every book takes me further from my “make it up as I go” pantser origins, and deeper into the realm of color-coded, hyper-organized outliner, and King definitely supercharged that! From a craft and joy perspective, I’m a huge fan of Jennifer Lynne Barnes’ Writing For Your Id talk. We decided early on to put as many of our own personal Id’s as possible into King – and I think you can tell!
Andrea: I think each distinct phase had its own process, or “flavor.” In the brainstorming phase, there was a ton of conversation and collaboration—texts, voice memos, comments, Google docs were flying all over the place. In the drafting phase, we each took ownership of our three characters and wrote our chapters separately. And in the revising phase, we combed through each other’s work, editing our characters’ actions and mannerisms, as well as focusing on certain plot lines and world-building elements we had each taken ownership of, making sure they flowed through each chapter and the entire narrative seamlessly.
What’s next for you?
Rebecca: Many things! I’ve got my next graphic novel for Neopets publishing November 4th. The sequel to I Killed The King will be out Fall of 2026, I’ve got a new middlegrade, Milo & The Monstrous Betwixt coming from Simon & Schuster in 2027, and I’m working on some other very fun projects I hope I’ll get to talk about soon!
Andrea: I’m in my Marvel era at the moment! The Grimoire of Agatha Harkness that I co-wrote with Danny Lore is coming out on November 11th this year on the tail of the Agatha All Along tarot deck that released in July. I get a bit of a lull to work on new projects before my next solo YA, The Fate of Winged Creatures, comes out from Wednesday Books in fall 2026.
Lastly, what books have you enjoyed reading this year? Are there any you’re looking forward to picking up?
Rebecca: Oh man, it’s been such a good year for reading! Some recent favorites: The Serviceberry by Robin Wall Kimmerer, Nature’s Best Hope by Doug Tallamy, The Tiger by John Vaillant, Everything Is Tubercolosis by John Green, and Be Ready When The Luck Happens by Ina Garten. I’m currently reading and loving two books: Sea of Grass: The Conquest, Ruin, and Redemption of Nature on the American Prairie by Dave Hage and Josephine Marcotty, which is staggeringly interesting for being a book about a bunch of grass, and VE Schwab’s wonderfully rich Bury Our Bones in the Midnight Soil!
I also adored the upcoming I, Medusa by Ayana Gray, The Everlasting by Alix Harrow, and To The Death by Andrea Tang! Definitely keep these on your radar!
Andrea: So! Many! Books! I am a huge fan of Mona Awad’s Bunny, so I’m very excited to dive into the sequel, which releases this month. I’ve also recently read and loved Erin Craig’s A Land So Wide and Xenobe Purvis’ The Hounding.
