"Wynonna Earp" follows the life of the great-great-granddaughter of famous lawman Wyatt Earp. After a troubled adolescence following the death of her father and the disappearance of her older sister Willa, Wynonna has inherited Wyatt’s mythic abilities and his famous gun - a Colt .45 revolver with a 12-inch barrel - along with his legendary old West enemies: Revenant demons.