In an attempt to find his fortune, young Michael Miner ventures into an old California gold mine to find any gold left over. After digging up what he thinks is gold embedded in a wall, the entire mine collapses around him, and he finds himself tumbling down a deep hole into. When reaching the bottom, he finds that he's stumbled into a large complex of caverns that houses the ruins of an ancient civilization! And where there are ruins, there's treasure, and Michael is not about to return to the surface empty handed...