Dark Rivers (Witchbane Series #3)

One hundred years ago, a sheriff's posse killed dark warlock Rhyfel Gremory, but his witch-disciples escaped, and their magic made them nearly immortal. To keep their power, each year one of the witch-disciples kills a descendant of one of the men in the posse, a twelve-year cycle that has cost dozens of lives, including that of Seth Tanner's brother, Jesse.

Seth Tanner uncovers the cycle of ritual killings that feeds the power of the witch-disciples, and he's hell bent on getting vengeance ...