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How Callie Hart Created the Worlds of Quicksilver and Brimstone 

Quicksilver author Callie Hart shared insight with E! News into the series’ worldbuilding, plus how the stakes for Saeris and Kingfisher are even higher in Brimstone, on shelves Nov. 18.

By Hayley Santaflorentina Nov 18, 2025 12:05 PMTags
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It took more than a little quicksilver to transport Callie Hart between worlds. 

In fact, when the author sat down to make her first foray into the world of fantasy with Quicksilver and its sequel Brimstone—out now—it was with a lifetime of inspiration that she brought to life the harsh desert world of Zilvaren and the verdant yet frosty Fae domain of Yvelia. 

“I read a lot of fantasy,” Callie told E! News in an exclusive interview. “Everything I've ever read colors what I write and my imagination.”

Specifically, she can point to the influence of her predecessors Frank Herbert and J. R. R. Tolkien

As she noted of Herbert’s work, “Dune had a big part of how I constructed Zilvaren and the landscape of it—very desolate and kind of haunting. I think everything finds a way of coloring how you write and what you create.”

And since Lord of the Rings has also played a huge role in Callie’s own reading and writing, she noted, “There's a couple of tips of the cap—more than a couple—to Tolkien, of course, the granddaddy of fantasy.”

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But while the landscapes and cities of Quicksilver and Brimstone may be an amalgamation of different influences, it was with a precise hand that Callie embarked on writing the fantasy series—a far cry from her self-proclaimed “very disorganized” approaches of the past.

“I have planned out the whole story,” she confirmed. “I was very aware that when you're dealing with such large world building, and a lot of through line stories, I didn't want to find myself in a position in book three where I'm like, ‘Oh man, I've really backed myself into a corner here and I and I don't know how to fix this.’”

Amanda Edwards/Getty Images

“So I definitely plotted out the beats of it and the really key important moments,” she continued. “And there are points at the genesis of this story that are very fundamental to how the book is going to end. So yes, for the first time in my life, I was organized.”

Plus, in addition to wanting to make sure her world building was thorough and immersive, the 41-year-old was aware of what she called the potential “pitfalls” of drafting the second book in a trilogy—especially when readers have fallen so deeply in love with the characters in the first. In this case, the enemies-to-lovers relationship between human Saeris and Fae Kingfisher. 

“They're notoriously hard to write,” Callie said of sequels. “It's hard to maintain a level of chemistry between the characters and also momentum in a storyline, because it's the middle book, and it's a weird place to find yourself in. In book one, you have the big hits—the first kiss, when they’re first intimate with each other, and that first ‘I love you’ exchange. Then in book two, sometimes it can feel a little flat. It's like, ‘Are we dating now? What are we? What are we doing?’”

But with Brimstone opening to a newly-changed Saeris—now half Fae and half vampire—and the implications of her and Kingfisher’s god bindings looming, Quicksilver’s sequel is anything but boring.

Forever/Hachette Books

Plus, the spice of the first book carries into the second—which was all part of Callie’s plan. 

As she explained to E!, “I wanted to crank up the chemistry between Kingfisher and Saeris to an 11.”

But whereas readers became accustomed to one version of Kingfisher in Quicksilver, with the introduction of his point of view chapters in Brimstone, fans are in for even more. 

“They’re going to meet a whole new version of him,” she revealed. “All throughout Quicksilver, Kingfisher is very guarded and not very transparent with his emotions—he's quite cold and distanced. And in Brimstone, we see him open up a little bit more and see how emotional he is and how vulnerable he can be, which I just—it's just beautiful getting to write those scenes.”

Brimstone has officially his shelves as of Nov. 18. And for more recently-released books to sink your teeth into after finishing, read on. 

Sweet Heat by Bolu Babalola

Release: Sept. 2

Years after the events in Honey & Spice, Kiki Banjo is at a crossroads in her career, is in the middle of a “Ross and Rachel”—a.k.a. on a break—with her tech bro boyfriend and is about to come face to face with ex Malakai Korede for the first time since their messy breakup years prior. And unfortunately for Kiki, unlike their relationship, their chemistry is very much alive and well. Babalola may be a self-proclaimed “Rom-Com Connoisseur” but she’s more than earned the title—and the very engaging and swoon-worthy Sweet Heat is just the latest proof.

 

The Wilderness by Angela Flournoy

Release: Sept. 16
A decade after her mesmerizing debut, The Turner House, Flournoy proves she certainly not hitting a sophomore slump in this dynamic, moving examination of friendship and life in an increasingly fraught 21st century. Following a group of Black women over the course of 20 years—spanning the 2000s through 2020s—the book delves follows the enduring bonds that may at times be tested but will hopefully never break.

 

The Wasp Trap by Mark Edwards

Release: Sept. 16
Someone just swiped right on a date with their demise. A group of friends who reunite to celebrate the life of their former professor learn there’s a more sinister reason for their meeting: they must revisit the pivotal year they joined forces to create the framework for a dating website—one that had an alternative use and had deadly consequences—or they will die.

The Academy by Elin Hilderbrand and Shelby Cunningham

Release: Sept. 16
Hilderbrand is swapping out the beach for back-to-school drama. The beloved beach read novelist teams up with her college-aged daughter on this new chapter in the classroom, following a scandalous year at an elite boarding school in Massachusetts.

 

Best Woman by Rose Dommu

Release: Sept. 23
Whether you know her from her Substack newsletter Mall Goth or X (formerly Twitter), Dommu knows how to capture an audience. And she brings that in full force with her delightful—and stressful at times—debut novel following Julia, a trans woman returning home to Florida to serve as the titular Best Woman at her brother’s wedding. With her high school crush serving as the Maid of Honor, Julia is ready for them to finally have their moment, prompting her to allow a white lie to spiral into something a whole lot bigger. It’s engrossing, at times stressful—in the best possible way—and is easily one of those books that you accidentally read in one sitting because you just couldn’t put it down. 

What We Can Know by Ian McEwan

Release: Sept. 23
In just under a century from now, a nuclear incident leaves the world decimated, mostly flooded and yearning for the past. Specifically, for Thomas Metcalfe, the early 21st century. However, has he dives into this past he’s so deeply romanticized and the scholars he idolized in search for the meaning behind a mysterious poem, his illusions are shattered and understanding of life during this time is irrevocably changed.

We Love You, Bunny by Mona Awad

Release: Sept. 23 
Prepare for a wild ride in this sequel to Awad’s 2019 novel Bunny—which also works as a standalone. In it, protagonist Sam has released a best-selling book inspired by her time with the Bunnies, think Heathers-level vapid but with some extra shocking secrets, only for the group to kidnap her so they can set the record straight and share the real story of the Bunnies. 

The Impossible Fortune by Richard Osman

Release: Sept. 30
After taking a break from the Thursday Murder Club’s shenanigans last year, Osman is back—without missing a beat. The gang—and their ever-expanding group of associates on both sides of the law—reunite at a wedding, only to be ensnared by a missing person case. As they mourn the loss of a loved one, this thrilling adventure may be exactly what they need to move into their next chapter together.

Heart the Lover by Lily King

Release: Sept. 30
King is back with another enthralling, character-driven story about love and friendship following the narrator, dubbed “Jordan,” and the two men she forms a deep connection with during their late college years. Spanning during that formative time and picking up decades later, the book is a deep reflection about those meaningful moments and how, for better or worse, they shape us.

Gone Before Goodbye by Harlan Coben and Reese Witherspoon

Release: Oct. 14
The celebrity book club maven becomes the author—joined by one of the biggest names in the thriller genre. It follows Maggie McCabe, a disgraced Army combat surgeon who becomes the provider for a mysterious patient, who subsequently disappears, leaving Maggie on the hook—and on the run. 

The Everlasting by Alix E. Harrow

Release: Oct. 28
In war-torn Dominion, the legend of Una Everlasting, the warrior who sacrificed herself for the good of the country centuries prior, endures—certainly more so than the true story of the woman herself. That is, until historian Owen Mallery gets sucked into the past, becoming entangled with Una. The pair are locked in a devastating time loop that in order to break, they must rewrite history.

Cursed Daughters by Oyinkan Braithwaite

Release: Nov. 4
Eniiyi is born on the day her mother’s cousin Monife is buried, leaving the family convinced she is Monife reincarnated—complete with the curse that will lead to her doom. However, desperate to avoid the same lonely fate, Eniiyi seems to break the curse that has plagued her family for generations, bringing deeply hidden secrets to the surface.

Fallen City by Adrienne Young

Release: Nov. 4
Romantasy’s latest It Couple may have just emerged. Luca and Maris fall in love just as the simmering tensions in their city Isara boil over and a rebellion breaks out, ultimately leaving them on opposing sides of the war. Still, they battle to find their way back to one another no matter the cost—even if that cost is everything.

 

The Strength of the Few by James Islington

Release Date: Nov. 11
Two years after Islington’s The Will of the Many, he’s back with the follow-up in his Hierarchy series, which picks up right where the cliffhanger left off. So, where does The Strength of the Few find Vis? Well, it takes readers far beyond the Ancient Rome-inspired empire of Caten and on an interdimensional journey to prevent an incoming Cataclysm.

Brimstone by Callie Hart

Release Date: Nov. 18 
Hart’s first Fae & Alchemy novel quickly took BookTok by storm last year, and now the story of Saeirs Fane and Kingfisher of the Ajun Gate continues, with Saeris as Queen of Sanasroth. But the threats to their realm are far from over. In fact, they loom larger than ever and it’s up to the lovers to find a way to save their people and their cities.

 

 

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