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.
Bela Lugosi
as Frank Chandler (Chandu)
Maria Alba
as Nadji - Princess of Egypt
Murdock MacQuarrie
as The Supreme Voice of Ubasti [Chs. 4-12]
Clara Kimball Young
as Dorothy Regent
Dean Benton
as Bob Regent (as Deane Benton)
Phyllis Ludwig
as Betty Regent
Lucien Prival
as Vindhyan, High Priest [Chs. 1-4]
Cyril Armbrister
as Henchman Sutra [Chs.1-4]
Wilfred Lucas
as Capt. Wilson [Chs. 4-12]
Josef Swickard
as Tyba, The White Magician [Chs. 8-12]
Baby Peggy
as Judy Allen
Dick Botiller
as Morta
