On an archaeological dig in Asia| Dr. Roger Bentley finds a cuneiform tablet referring to an ancient society| the Shadow Dynasty| that was destroyed. An earthquakesoon after reveals an ancient artifact and the scientists discover the ruins of an ancient temple world on a remote mountain site. It leads them to an undergroundworld| lost in time| where people have adapted to low light. The High Priest Elinu doesn't welcome the presence of the new arrivals and wants them eliminated.