Ralph Morgan as Kurt Ingston

Don Porter as Dick Baldwin

Irene Hervey as Dr. Lynn Harper

Fay Helm as Margaret Ingston

Nils Asther as Agor Singh

Doris Lloyd as Sarah Judd

Leif Erickson as Laurie

Robert Homans as 'Cap' Beggs

Lionel Atwill as Dr. King

Frank Reicher as Dr. Timmons

Francis Pierlot as Dr. Phipps

Bela Lugosi as Rolf

Eddy Waller as Jeb Harmon

Janet Shaw as Milly Carson

Cyril Delevanti as Torque