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