Mostly told from Jaibriol III's POV from the time the Eubians recapture his father, through his decision to trade (pun intended) himself for his uncle Eldrin, his investiture as the Emperor of Eube, and his marriage to Tarquine Iquar. From the flaps of the Tor first edition: "... With The Moon's Shadow, Catherine Asaro begins a thrilling new chapter in this galaxy-spanning epic, as the titanic conflicts which have raged across the cosmos at last come to a climax. At the age of seventeen the young nobleman named Jaibriol Qox becomes ruler of a vast galactic empire - and loses everything he has ever valued. Born of a clandestine liaison between a renegade daughter of the Skolian Imperialate and a scion of the genetically engineered Eubian Traders, Jai Qox grew up in exile, unaware of the powers that coursed through his noble blood. In the waning days of the bloody Radiance War that ravaged the galaxy, Jai was captured and returned to the Traders to play a role as a puppet Emperor in their scheme to consolidate their domination of space. Now Jai must walk a razor's edge, to seize the power that is his by birthright without succumbing to its dark seduction and wield it for the good of all, and to avert a conflagration that threatens to engulf a thousand worlds."
Source · ISFDB CC BY 4.0