You'll Find Out [80720] Released: 1940-11-22 Revenue: $0 Budget: $0 Profit: $0 Runtime: 97 mins Popularity: 1.0286 Vote Average: 5.458 Vote Count: 24 Overview: The manager of Kay Kyser’s band books them for a birthday party bash for an heiress at a spooky mansion, where sinister forces try to kill her. Cast [33] Kay KyserHimself Peter LorreProfessor Karl Fenni Boris KarloffJudge Spencer Mainwa Bela LugosiPrince Saliano Helen ParrishJanis Bellacrest Dennis O'KeefeChuck Deems Alma KrugerAunt Margo Bellacres Joseph EggentonJurgen Ginny SimmsHerself Harry BabbittHimself M.A. BogueIsh Kabibble Sully MasonHimself Mary BovardMary Jeff CoreyMr. Corey Louise CurrieMarion Bess FlowersLady In Taxi Jeanne HouserJean Richard KiplingScript Man Eleanor LawsonMs. Gaby Lawson Larry McGrathApartment Complainer Frank MillsCabbie Mimi MontayeMimi Dorothy MoorePenny Leonard MudieReal Karl Fenninger Joseph NorthServant Frank O'ConnorApartment Responder Beulah ParkingtonMother Jane PattenJane Eugenia RafeeFrench Maid William TelaakMac Joan WarnerJoan Guy WebsterInfant Mary Martha WoodGeorgia Trailers Joe Dante on YOU'LL FIND OUT You'll Find Out - Movie Trailer (1940)