While blasting, a mining team inadvertently causes a rock slide that opens the side of a mountain exposing a large valley. A short while later the Calico runs aground in a river and while exploring the nearby area wanders into the opening and discovers a valley full of giant plants and insects. While attempting to save the team Godzilla is initially paralyzed by a Black Widow Spider bite. During the battle to save the team the only means of escape is blocked so the team must find a way to escape and also prevent the insects from escaping the valley.