Oath of Fealty — Elizabeth Moon

Thanks to Paks's courage and sacrifice, the long-vanished heir to the half-elven kingdom of Lyonya has been revealed as Kieri Phelan, a formidable mercenary captain who earned a title--and enemies--in the neighboring kingdom of Tsaia. Now, as Kieri ascends a throne he never sought, he must come to terms with his own half-elven heritage while protecting his new kingdom from his old enemies--and those he has not yet discovered.

Meanwhile, in Tsaia, Prince Mikeli prepares for his own coronation. But when an assassination attempt nearly succeeds, Mikeli suddenly faces the threat of a coup. Acting swiftly, Mikeli strikes at the powerful family behind the attack: the Verrakaien, magelords possessing ancient sorcery, steeped in death and evil. Mikeli's survival--and that of Tsaia--depend on the only Verrakai whose magery is not tainted with innocent blood.

Two kings stand at a pivotal point in the history of their worlds. For dark forces are gathering against them, knit in a secret conspiracy more sinister--and far more ancient--than they can imagine. And even Paks may find her gods-given magic and peerless fighting skills stretched to the limit--and beyond.