Greed, ambition and hunger-for-power drive John Hart, a New-York-City stock-market broker, into crooked dealings and deception, but he doesn't realize that those he ruined will seek vengeance. He meets his match and downfall when his path crosses with a reporter, Phil Stuart; a girl, Marcia Harper, and a man-with-a-gun from a family he ruined.

Chandu consults his crystal ball and sees that Nadji, Princess of Egypt, is in danger. She is about to be sacrificed by the black magic cult of Ubasti. Headed for the magic island of Lemuria, he is shipwrecked , washed ashore and captured. He becomes invisible, escapes and after numerous detours is able to rescue the princess.