Inspector Peterson
Kara Niemann
Dr. Nils Ahlen
Sven Nystrom
Helga Ahlen
Baroness Erland
McTavis, ferry pilot
Trerik
Chief of the Lost Valley
Det. Holt
Det. Anderson
Prof. Lind
Director-General of the Research Inst.
Anders
Colonel Strand (uncredited)
Noma (uncredited)
Minor Role (uncredited)
Frau Lind (uncredited)
Bertil (uncredited)