Hero's Song (The Songs of Eirren #1)

Nessa, Collun's beloved sister, is gone. Disappeared -- without a trace. Collun knows he must search for her, but he can't seem to go; he's always considered himself a coward.

Then one day the kesil, a wild forest man tells Collun, "You know what you must do," gripping his arm tightly. "Do not delay longer."

So Collun travels northward, facing increased dangers from the forces of darkness. He has become involved in something much larger and more evil than he ever imagined.

(summarised from the cover)