The ivory key
(Book)

Since the murder of the maharani of Ashoka--the country that controls all magic--the relationships between the royal siblings have fractured. At only 18, Vira has ascended to the throne, a role few in her council believe her capable of. Meanwhile, her twin brother, Ronak, is plotting to break free from a tactful marriage and taking their half-brother, Kaleb, (wrongfully imprisoned for the maharani's assassination) with him. The siblings' unease comes to a head when their sister Riya returns to the palace after two years of running with a group of rebels. As Ashoka's quarry runs out of magic, the only option left is to find fragments of an old map leading to an ivory key rumored to unlock the lost quarries of Ashoka. Legend or not, all the siblings want a piece of it.