The Deer King, Vol. 2 (Novel): Returners Volume 2

Van's chase to rescue the kidnapped Yuna leads him to the Ahfal Oma, the People of the Fire Horse. They reveal that the sickness plaguing Aquafa is no random resurgence but a carefully orchestrated revenge plan, and they want the leader of the Lone Antlers to join. Van can't abide a destructive quest that threatens all of Aquafa, but he's still only one man. And how can a single man stop a disease--especially one that already lives within him?