Halcyon and Evadne live in a world with magic- for a select few, who are born as mages. This ability manifests when they find they are unable to write, as their words slide off the paper. Mages have magic in their words and songs. Evadne desperately wanted to be a mage, but it was not to be- her older sister Halcyon comforted her with an invented language of their own. Halcyon was strong, bold, and fearless, heading off for the military where she was destined for great things.
What I loved: The world-building is lush and compelling; the reader learns about magic, its manifestation in mages, and the artifacts that can be used to certain ends. The true strength of the story is in the sisterly bond between Halcyon and Evadne that shines throughout the book. Their connection is beautiful. While other characters are also fantastically built, the book manages to come back to the theme of sisterhood and its unbreakable bond.
The book also touches on other themes such as corruption, morality of power/magic, and punishment- the weight of it and the way that it can change a person. These themes are woven within the overarching story of love, action, and adventure that make it really thought-provoking.
What left me wanting more: There are a few things that I wish had more lead-up, such as Evadne's decision in the courtroom, the romance that builds, and Straton's feelings towards Halcyon. While we get glimpses of this, I felt that more internal thoughts/motivations or lead up to the decisions would have been helpful as they sometimes felt a bit blunt/shocking. I also would have loved to hear some of the mythology of the gods who left the relics/artifacts behind, because this world really fascinated me, and more history would have been intriguing.
Final verdict: Overall, SISTERS OF SWORD AND SONG was a beautiful tale of sisterhood and the power of that unshakable bond. Highly recommend for fans of YA fantasy.