Ruth Roman as Ann Hemple Nicholson

Sterling Hayden as John Emmett

Werner Klemperer as Dr. Frederick Simmons

Richard Gaines as Dean William Brant

Charles Davis as Edward Manning Kirkpatrick aka Kirk

Jeanne Cooper as Helen Bethke

Peter Hansen as Karl Plesser

Karl Ludwig Lindt as Dr. Reinhart Kissel

John Mitchum as Bud--Deputy Sheriff

John Frederick as Sheriff

Leonard Bremen as Collision Shop Owner (uncredited)

Sidney Clute as Mechanic (uncredited)

Ken Curtis as FBI Agent Jim Anderson (uncredited)

Harry Hines as Motel Owner (uncredited)

Tom McKee as Man from Sanitarium (uncredited)

Bert Stevens as Motorcycle Cop (uncredited)