Richard Haydn

as Herr Falkstein

as Quentin Bartlett

as Rupert Rowbotham

as Max Detweiler

as William Brown

as Sir Henry Vining

as Prof. Summerlee

as Alfred North

as Bertie Searles

as Christopher Wellington St. John Denny

as Baron Popoff

as Caterpillar (voice)

as l'empereur François-Joseph

as Clarence Appleton

as Earl of Radcliffe

as Andre LeBlanc

as Deputy Commissioner Hewitt

as Horatio Willing

as Dr. Chisholm

as Jason Reid

as Jonathan Wilson

as Limo

as Thomas Rogers

as Specialty

as The Victim (voice) (uncredited)

as Roger Winant

as Prof. Oddly

as Charley Wyckham