Castles in their Bones Books in Order

Laura Sebastian's Castles in Their Bones is a YA fantasy trilogy about three sisters raised to be weapons of empire. Sophronia, Daphne, and Beatriz are triplet princesses from Bessemia, and their mother, Empress Margaraux, has spent their whole lives preparing them for one job: marry into rival kingdoms, destabilize them from within, and help her claim the continent of Vesteria.

The sisters have been trained in charm, deception, violence, and courtly performance. Each has a different assignment and a different strength, so the first book follows them into three very different royal settings. Sophronia is sent to Temarin, where letters from her intended husband have made the mission feel more personal. Daphne enters politically unsettled Friv. Beatriz arrives in Cellaria, a place where magic is feared and tightly controlled.

Their mother expects obedience. The stars have other ideas.

The series gets much of its momentum from the gap between what the princesses were taught to do and what they begin to want for themselves. They are spies, future queens, daughters, and sisters, often all at once. Their separate missions leave them isolated, but their bond remains at the center of the story, especially as secrets, loss, and their mother's larger plans come into view.

Vesteria is built around competing courts, old grudges, uneven power, and customs that change from country to country. Magic matters too, particularly the mysterious wishes connected to the stars and the abilities that some rulers would rather suppress. The books use that broad setting for plenty of disguises, negotiations, rivalries, romantic complications, and shifting loyalties without losing sight of the emotional stakes between the sisters.

Expect a fast-moving fantasy with multiple points of view, palace intrigue, espionage, and a steadily widening conflict. Castles in Their Bones begins with the triplets' arranged marriages and divided loyalties. Stardust in Their Veins follows the fallout as the surviving sisters question everything they were told. Poison in Their Hearts brings the trilogy's struggle over Vesteria, fate, and family power toward its final confrontation.

It is a series about girls who were taught that love is a weakness, then have to decide whether trust might be the thing that saves them.