For anyone that devoured Brimstone in a weekend, you're probably wondering, 'when will I get my hands on the next one'? And you're not alone.
Booktok readers emerging from the Fourth Wing and ACOTAR haze, looking for their next tome, immediately locked onto Callie Hart's Quicksilver. It's the tale of Saeris Fane, a woman living and surviving in the poorest part of her segregated city. After an encounter with one of the Queen's guards gone wrong, Saeris is faced with a deadly situation that would see her pulled into pool of molten quicksilver and into another realm.
Both Quicksilver and its follow up Brimstone make up the first two instalments in what is set to be a trilogy called The Fae & Alchemy trilogy. The story's rabid popularity meant that both books have become New York Times best-sellers. Now, fans are waiting with bated breath for any news about the third and final book in the series.
We've done some digging and trawled through some reddit threads. Here's everything we know so far about Quicksilver book three.
When can we expect the third book to come out? The date was pushed back
Callie Hart finally made an announcement about the release, and it's later than we expected. Expect book three in September 2027. The author took to Instagram to announce the news.
View this post on Instagram
Hart said of the decisions to push the date back :"this has been a super tough decision to make, but one that feels necessary."
"Let’s be real. Pushing out a release date sucks. It sucks for you guys, and it sucks for me. I want nothing more than to release book three tomorrow and unload all of these crazy plot twists on you guys, but since this is the final instalment in Saeris and Kingfisher’s trilogy and it’s so much bigger than books 1 and 2, I really want to make sure the story is perfect."
Quicksilver was initially released on 4 June 2024. Brimstone was released on 18 November 2025. This is roughly a 17 month gap between books. If we follow the same pattern, the third book was due April 2027. Waiting an extra five months is minimal in the grand scheme and it is always a positive step for authors to get the time they need to work on their craft.
The third book did actually go up for pre-order on Barnes & Noble with a note saying the item will be released on 10 November 2026. Hart acknowledged this in her Instagram post, but confirmed the new September 2027 release date.
We do know that Callie Hart is already deep into writing the next instalment. Weeks before Brimstone was released, she posted to Instagram letting fans know that writing the third book was no mean feat.
View this post on Instagram
As fans, we don't want our favourite stories rushed through, only to get our hands on a story that doesn't match our expectations. All good things take time and Kingfisher fans are happy to wait to see how the trilogy comes to a close.
Do what know what it's called?
We don't have a title yet, but given the current naming pattern – Quicksilver and Brimstone – we have to assume the name will relate to another magical element or skill. Maybe the name could draw on Kingfisher's powers to manipulate shadows? Or the name might relate to alchemy and Saeris's powers as an alchemist.
What details do we have so far? What will it be about?
It's hard to find any concrete details.
Callie Hart said on her Instagram "Book three is a leviathan. It will eat me. Or you. Either way… sorry." Given that a leviathan is a kind of sea demon, we assume she's saying writing the book is its own beast. It will likely be the longest book in the series.
It's set to be a frustrating wait for more details. Especially considering the sizeable cliffhanger we were left with at the end of Brimstone. We last saw the now-Queen Saeris and "Kingfisher" (if you know, you know) facing off in the demon-realm of Diaxis against a dragon who demands a hefty bargain from the pair.
Is book three the last book in the series?
Yes, this is supposed to be the last book. While other popular romantasy series are longer – like Fourth Wing which is set to have five books and ACOTAR which will apparently have six – this will be it for the Quicksilver books. Author Callie Hart planned the Fae & Alchemy series as a trilogy, so this coming book is set to be the last one.
But you never know. Mortal Instruments was supposed to be a trilogy but then author Cassandra Clare ended up writing three more.
