Jan Trevor
Noah Beery Jr.
Mona Andrews
Dorothy Short
Henry Andrews
Russ Powell
Dr. Carl Neff
Don Brodie
Harry Worth
Jan Trevor as a Boy
Dickie Jones
Gen. Tichak
Eddie Kane
Emperor Mena
Stanley Andrews
Navigator (archive footage)
Richard Alexander
Dr. Pierce
King Baggot
Speaker at Conference
J. Frank Glendon
Guard of Mu
Al Ferguson
Borno
Harry Woods
Doctor at Conference
Eric Mayne
Freighter Captain
J.P. McGowan
Grubb, Freighter's Mate
Charles Murphy
Emperor's Guard / Mu Sentry
Eddie Parker
Batu
Buddy Roosevelt
Lancer Officer-in-Charge
Hal Taliaferro
Mrs. Henry Andrews
Gwendolyn Logan
Kutu
H. Burroughs
Dr. Harry Trevor
Bryant Washburn
Dr. Frank Bracken
Walter Miller
Prince Samu
John Davidson
Dr. Charles Phillips
Fred MacKaye
Georgia Trevor
Viva Tattersall
Allen
William Desmond
Mrs. Camerford Amster
Grace Cunard
Director
Lew Landers
Writer
Basil Dickey
Producer
Milton Gatzert
Cinematography
William A. Sickner
Editor
Alvin Todd