The brutal Dr. Nishikiori forcibly marches Akira to the base of a huge pyramid, where he finds a mummified skull with huge fangs and scales. With Ohmori as a hostage, the doctor orders Akira into a narrow underground passageway. At first Akira thinks Nishikiori's just trying to get him out of the way, but soon he uncovers a secret that will turn everyone's ideas about the island upside down!