I struggled with this prompt for a little while since while I love stories about BFFs, I sadly didn’t have many to recommend. So behold, instead, a post about duologies:

- The Greenhollow duology by Emily Tesh
Two delightfully lush, woodsy and queer stories about the Green Man, Tobias and his lover Henry. As well as the romance, this duology is well worth reading for Henry’s mother, the indomitable Mrs Silver - The Philosophers series by Tom Miller
This series is one of my all time favourites. I love the alt!history premise and the characters all leap off the page, while the author’s expertise in emergency medicine also shines through. - The Watchmaker of Filigree Street by Natasha Pulley
Natasha Pulley has gotten better with time, and while these aren’t my favourite of her books, many of her trademarks are already there: the quiet, contemplative atmosphere, the musings about language and communication, and the slow-burn romance in particular. - A Conspiracy of Truths by Alexandra Rowland
I love the enormity of the world-building in this series, and there’s also some fantastic humour underneath. The first book was good, but the second book stole the show for me, thanks to Ylfing, whose continued desire to right wrongs (regardless of who made them) is incredibly uplifting. - The Shadow Histories by H.G. Parry
Firstly, I’m still mad that Parry made me have a bunch of feelings about William Pitt, of all people. Secondly, this series is a great example of how a duology can be used to play with reader expectations. I enjoyed the first book, but thought it was far too white male centric; so of course the second book flipped that narrative and focused on why ignoring other voices is a complete folly. - Sorcerer Royal by Zen Cho
A fantasy of manners duology that focuses on people of colour and queer people in Britain. I didn’t like the second book as much as the first – because no one can beat the delightful pairing of Zacharias and Prunella, who I wish had been the stars of both books – but I’m still recommending it for a series that does something different with the genre. - Teixcalaan by Arkady Martine
It’s hard to put into words why these books are so good – though to start with Martine uses words to much better effect than I do. I really enjoyed the political intrigue element of the story, the focus on world-building through cultural institutions, and of course the burgeoning relationship between Mahit and Three Seagrass. - Poison Wars by Sam Hawke
I really loved seeing the evolution of Hawke throughout this series from good debut author to talent to watch. This series is full of unique world-building, excellent disability representation, and engrossing political intrigue. - These Violent Delights by Chloe Gong
This is excellent retelling that makes the Romeo & Juliet story its own without losing the original themes. I particularly enjoyed the detailed Shanghai setting, and the story itself is fast-paced with plenty of twists and turns. - Clocktaur War by T. Kingfisher
This duology is more like one story split into two books, so I recommend reading them closely together. It’s not the most unique story on this list, but it’s so much fun – there is plenty of action, witty banter and romance.