In Shadow Runner, a noble-born girl raised as an assassin must choose between escaping a life of violence or protecting the two she loves most—her adopted sister and her captor. Author KJ Fieler talks to Book Glow about the book.

Describe the book in one sentence.

Shadow Runner follows Ada, an aristocrat turned assassin, as she fights to reclaim her freedom in a world where loyalty is lethal and secrets are currency.

What led you to write it?

I’ve always been intrigued by the conflict between personal identity and societal expectations, and how the two often clash in ways that can be both transformative and devastating. Writing Shadow Runner was a way for me to examine themes of freedom, loyalty, and the moral choices that define us, all while creating a character who is pushed to the edge of her own identity.

Which authors or books most influenced your voice and why?

Margaret Atwood for her precision, Neil Gaiman for his sense of wonder and darkness, and Shirley Jackson for her ability to unsettle with the quietest of details. They taught me that language can be both beautiful and brutal at once.

How do you organize your writing day—do you have rituals or routines?

I start early, always with coffee and a playlist that matches the emotional tone of the scene I’m working on. I block off a few hours in the morning for pure drafting and save editing for the late afternoon.

What does your research process look like (for historical settings, technical details, etc.)?

It’s a rabbit hole! I start broad—reading articles, books, and interviews—and then narrow into specific questions that come up as the story demands. I also love consulting experts whenever I can; hearing how someone talks about their passion gives depth that internet articles and textbooks can’t.

Which character in your book was the most fun (or challenging) to write, and what made them so?

The most fun to write was Dieb, a street waif with a sharp edge and surprising moments of vulnerability. She’s a character full of contradictions, and those unexpected layers made her a joy to bring to life. The most challenging character to write was Ada. Her internal struggle to survive a brutal situation without losing her humanity often felt like walking a tightrope. Capturing the balance between her strength and vulnerability in a way that honored her journey required constant care, as I had to ensure her complexity was never lost in the darker moments she faced.

What themes or questions are you most interested in exploring through your work?

I’m deeply drawn to themes of identity, loyalty, and survival—how these forces shape us and force us to confront who we are at our core. I’m especially fascinated by the gray areas between right and wrong, and how people navigate the blurry line between good and evil when their survival is at stake. I also ground my work in contemporary issues like women’s rights and societal struggles, weaving them into narratives that reflect the complexities of our world and the challenges we face today.

Is there any one thing that especially frustrates you about the writing process?

The part where I know what the story could be, but my early drafts are still stumbling to catch up. It’s hard to sit with the imperfections, but that’s where the magic eventually happens.

What’s the toughest hurdle you’ve faced during your writing career, and how did you overcome it?

Self-doubt, absolutely. I overcame it (and still do, daily) by reminding myself that the work doesn’t have to be perfect—it just has to be honest. Showing up every day, even when it’s hard, is a quiet kind of victory.

Any advice for novice writers?

Protect your love for writing. There will be critique, rejection, and days it feels impossible. But if you can stay in touch with the joy that made you start, that’s the part no one can take from you.

What do you hope readers take away from your book?

That identity is rarely simple, loyalty often costs more than we expect, and that even in the darkest moments, there’s a chance for redemption.

What’s next?

Shadow Hunter (book two) is complete and currently in the editing phase. Ada, Dieb, and Aldrik are back, with Ada and Dieb navigating the complexities of their relationship, while Ada finds herself drawn to Aldrik, struggling to resist his undeniable charms. I’m also deep into the final novel in the trilogy. End of Shadows (book 3), set at the beginning of the women’s movement, is an even more intricate and perilous tale exploring power, forgiveness, and the true cost of personal freedom.

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