Walter Connolly

as John Forrester aka Eric Jann aka Peter Korotoff

Doris Kenyon

as Margaret Forrester

Robert Young

as Jack Forrester

Scotty Beckett

as Jack Forrester, Age 4

Henry Kolker

as Carlo - the Puppeteer

Akim Tamiroff

as Peter Korotoff

Gilbert Emery

as Professor Weaver

George Humbert

as Niccoli