Sovereign silk Silken magic series, book 3.

Sovereign Silk is the third book of a series set in the mythical kingdom of Tyrrhia, where courtly politics, magic, and the silk trade intersect. The very future of Tyrrhia is endangered when assassins target Alban, the beloved king, while his wife, Queen Idala, lies on the brink of death after giving birth to quadruplets whose conception was marked by dark magic. With the king and queen's firstborn son far too young to assume the throne should...