When mania creates a monster, only one man can stop the killing.

1483, Cordoba, Andalusia. Surgeon Thomas Berrington makes a reluctant journey to Qurtuba at the request of his master. He expects only to operate on a Spanish prince and return home to Moorish al-Andalus. But fate has something else in store for him and his companion, the eunuch Jorge.

A warped killer is taking young women to create twisted creatures from their bodies. When Thomas is tasked by Queen Isabel to hunt down the culprit he is propelled into an unfamiliar world of religious mania where it is impossible to tell who is friend and who foe. Meanwhile, Jorge is on a quest of his own—to track down the remnant of a family he abandoned twenty years before.

When the Bonebreaker takes a new victim the pair are forced to undertake their most dangerous challenge yet. Thomas and Jorge race to expose the killer before yet another life is taken – this time someone close to them.