Callie Hart’s highly anticipated Quicksilver sequel, Brimstone, is set to release in November 2025, leaving fans plenty of time to catch up on the popular BookTok romantasy read ahead of its publication. While not much has been revealed about the upcoming narrative, Callie Hart’s previous Brimstone tease hinted that the book would be absolute mayhem from page one, stating that the story will kick off with “all gas, no brakes.” Knowing this, fans have begun to share Quicksilver theories online, and there’s one I am absolutely convinced by.

The ending of Quicksilver was incredibly fast-paced and packed with action, and in the aftermath of several pivotal scenes, Saeris is revealed to have been turned into a half-fae, half-vampire hybrid. While Zareth, the god of chaos, is responsible for making her into something rare, it was Taladaius who first bit Saeris at the end of the novel and began her vampire transformation. One Reddit theory suggests that, because Taladaius is responsible for turning her into a vampire, he and Saeris will have a romance arc in the upcoming Quicksilver sequel — and after looking into it, I believe it’s a possibility.

Quicksilver’s Saeris & Taladaius Romance Theory Makes So Much Sense

Similar to Everlayne, Saeris Has Become Sired To Taladaius

Quicksilver‘s ending is a whirlwind of high-stakes events, but when Saeris finally awakens after emerging from the pool of quicksilver, she finds she has become half-fae and half-vampire. Not only that, but she was turned by Malcom’s second in command, Taladaius, who is seemingly an ally and friend to Kingfisher. Earlier in the novel, Hart explains that someone who is bitten by a vampire becomes enthralled by them, essentially making them extremely submissive and willing to please them. Taladaius even confirms this, stating he is now her sire, giving him control over her memories and agency.

“And, well, it is in a sire’s power to suppress those memories, if—”

– Taladaius, Quicksilver

This development has caused many fans, including myself, to consider the fact that Taladaius might act as a new love interest in Brimstone. Not only is it confirmed that Saeris is sired to Taladaius, but the two characters’ interaction at the end of the novel is peculiar. Given Saeris almost dies at the end of Quicksilver, I was surprised to find Kingfisher was not the first person she awoke to see. Instead, Taladaius is watching vigil over her with an amused expression, and he even reveals that she bit him as well — although it’s not yet clear what this could mean.

I’m Worried For Saeris & Kingfisher’s Relationship In Brimstone If This Theory Proves True

Saeris’ Sire Bond Might Put A Wrench In Their Relationship

When Saeris and Kingfisher finally do unite at the end of the novel, Saeris is visibly relieved — but she notes that Kingfisher has a stony expression, only giving her the faintest of smiles. His whole demeanor during this scene seems strained, and while it’s possible he’s just feeling guilty over making the decision to turn her, I think it’s possible he knows the consequences of that choice will be great. Saeris is new to the world of the fae, and she knows little about vampires and sire bonds. But I believe Kingfisher understands the full scope of what it means.

This makes me incredibly worried about Saeris and Kingfisher’s relationship in Brimstone, especially after the two finally accepted their mating bond at the end of the first novel. Their relationship has already gone through some major ups and downs, but being sired to another man may cause even greater relationship issues throughout Brimstone. While Kingfisher seems to trust Taladaius, even he can’t predict how strong their vampire sire bond will be in comparison to his and Saeris’ mating bond. But what worries me most is that only one of the two bonds has the power to control another.

This Quicksilver Theory Would Completely Upend The Fae & Alchemy Series

This Plot Twist Would Be Devastating To Kingfisher Fans

Ever since Sarah J. Maas completely blindsided readers with A Court of Mist and Fury‘s Feyre and Rhysand plot twist, I’ve been hesitant to believe any romance arc authors initially introduce to a novel. However, if Hart was to pull off something similar in the upcoming Quicksilver sequel, I believe it would be even more devastating — especially as Kingfisher quickly became a favorite book-boyfriend after Quicksilver‘s release. Unlike ACOTAR‘s Tamlin, Kingfisher’s character is intriguing, complex, and has so much depth in the first novel. I think readers will have a really hard time accepting anyone in his place.

However, knowing Hart plans to build out the Fae & Alchemy series over the course of three books, it’s not necessarily outside the realm of possibility. Taladaius is a virtually unknown character at this point in the series due to him only making an appearance at the end of the novel. So, it’s possible that Brimstone‘s narrative will flesh out his character in more detail and help convince readers of his and Saeris’ potential romance storyline.

While I’m intrigued to see how this could play out as a potential plot foil, I’ll definitely be upset if Saeris and Kingfisher aren’t endgame. It would be difficult to pull off that particular twist, even if it was handled correctly. Of course, other romantasy series have managed it before. Only time will tell if readers can get on board with a romance subplot between Saeris and her new sire, and Brimstone‘s approach to the situation will be the determining factor.

A Romance Curveball Could Work For Brimstone If It’s Handled Correctly

Hart Would Need To Sell Readers On Taladaius’ Character

As of right now, I have zero emotional attachment to Taladaius’ character. And if Hart is planning to introduce him as a secondary love interest in Brimstone, she will need to sell readers on his character and develop a strong relationship between him and Saeris, similar to how Maas’ A Court of Mist and Fury does with Rhysand. For this type of plot twist to work well, readers need to fully understand and come to know Taladaius, which seems entirely possible, since Brimstone‘s cover blurb hints that Saeris and Kingfisher will be separated for most of the novel.

Now that Saeris is queen of the Blood Court — and the vampires — it’s possible her and Taladaius will be spending a lot of time together throughout Brimstone. As Saeris ascends the throne and begins to rule, she will need to lean on Taladaius’ knowledge of the court and depend on him as an ally, giving them plenty of time to become well acquainted. And if this is the route Hart plans to take in the Quicksilver sequel, she will need to progress their relationship organically, as anything forced won’t translate well for readers throughout the narrative.