The Great Leader summons Baron Fang, the great Doovoo shaman of the Tusk Tribe from the upper reaches of the Congo River, to become commandant of Destron Japan. His mutant Skull-Warthog uses his tusks to dissolve human flesh from their bones. In order to lure Kazami Shiro to his doom, Skull-Warthog possesses the body of Rider Scout Toshiko's father and kidnaps her mother. Shiro and Sakuma Ken come to her aide, but are soon surrounded by the villagers who fall under the sway of the Devil's Drums�