When Kaspar Hauser (Bruno S.), a young German man, is suddenly released from an existence of inexplicable confinement, he is forced into regular society. Barely capable of communicating, Hauser is exploited in a circus sideshow until he is taken under the wing of the kindhearted Professor Daumer (Walter Ladengast), who slowly helps him acclimate to conventional life, even teaching him to read and write. Despite his best efforts, however, Hauser may not be able to escape the horrors of his past.