The Bone Shard Daughter has multiple POVs: Lin, the emperor's daughter on Imperial Island; Jovis - the smuggler who only wanted to be a sailor with his wife; Phalue - the governor's daughter who was known for changing partners until she met Ranami; Ranami who doesn't want to be a wife to a future governor; Sand - who spends her days doing the same old chore until she falls off a tree and it stirs up her memories (Maila Isle). They live on different islands, but Phalue and Ranami live together on Nephilanu Island.

Sukai's dynasty is currently ruling, and the emperor is still afraid of their enemies - the Alanga. They had defeated the Alanga a long time ago, but the Alanga artifacts and murals remain a grim reminder of all that's happened. As long as the artifacts stay quiet and motionless, they are safe. We don't get any backstory; the plot focuses on events in different parts of the Empire. The emperor builds constructs from animal parts by harvesting human bone shards, inscribing magical commands on them, and burying them deep into the animals' flesh. The constructs answer to him only. Most people fear constructs because of their horrifying appearance. Most contain body parts from different animals, making them even more unnatural. There are four dominant constructs (bureaucracy, war, trade, and spies), and many others deal with smaller tasks. Lin has always felt pressure to be good enough for her father, to be a worthy heir to the throne, but the emperor has given more attention to her stepbrother Bayan. When they were little, Bayan got sick with a mysterious disease, carried it to her, and it caused her immense memory loss. She was never able to retrieve those memories despite her father's punishments and promises that were she ever to gain the memories back she would be of more use to him. Lin decides to trick her father, study the art of creating constructs, and turn his design against him.

Jovis was living his smuggler life on the run from Ioph Carn when he found himself on Deer Island. Someone commissions Jovis to save their child from the ceremony of harvesting bone shards. He never wanted to be a savior, but he needed the money. Something odd happens that day, which causes the whole of Deer Island to sink into the Endless Sea, and he barely escapes. While sailing away with the child he saved, he gains an unexpected animal friend. The child names the marine creature Mephi. Mephi proves more than once to be a good friend to Jovis and a source of this new power within him. The memories of his wife, Emahla, who disappeared years ago, haunt Jovis. He desperately wants to trace down the boat with blue sails to the furthest corners of the Empire to find his missing wife. Will he be able to bring her back?

Lin and Jovis' plotlines make up most of the story. Phalue and Ranami are relevant side characters, and their story revolves around Phalue gaining the courage to bridge the class differences between her and Ranami. Ranami is from a lower class and barely secured a decent job. Phalue has always had everything served on a silver plate. Ranami knows there is not much Phalue can do about her upbringing, but she begs her to put herself in the shoes of the workers' class to see how her father treats them. Sand's plotline is the most mysterious one. She gets fewer chapters, but every time we return to her, she has made more progress in changing her life.

The plot is well crafted, full of adventure, fighting, emotional scenes, character growth, and many plot twists. I've had the best time reading this. It's rare for me to like every single character in a book, but that's true in this case. I felt connected to all of them in one way or another and was excited to see how it would all wrap up. I did predict one of the plot twists, but the rest were surprising and evoked genuine shock. The writing is solid. My only wish is to see more of Phalue and Ranami in the next book. I wanted more scenes of pure tender romance among the constant arguing.
I am so happy I picked this book up on a whim and will continue the series.