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.

Kay Kyser
as Himself

Peter Lorre
as Professor Karl Fenninger

Boris Karloff
as Judge Spencer Mainwaring

Bela Lugosi
as Prince Saliano

Helen Parrish
as Janis Bellacrest

Dennis O'Keefe
as Chuck Deems

Alma Kruger
as Aunt Margo Bellacrest

Joseph Eggenton
as Jurgen

Ginny Simms
as Herself

Harry Babbitt
as Himself