Gryphon in Light (Kelvren’s Saga 1) - Mercedes Lackey

On the border between Valdemar and the deadly Pelagirs Forest, the gryphon hero Kelvren returns from a near-fatal self-sacrifice that won him the approval of Valdemar’s ground troops, but caused a diplomatic crisis. Frustrated by his lack of a hero’s welcome, Kelvren is talked into helping with an expedition by his old friend, Firesong.