The film reports on the development of the Berlin zoo. A sparrow tells the story of Berliners' love of animals. Many visitors seek joy and relaxation in the zoo every day. Above all, Berliners are happy that they created the park themselves.
A mad doctor uses patients at his isolated psychiatric institute as subjects in his attempts to create longevity by surgically installing an artificial gland in their skulls.
Young forester Sixt is wounded one night. Smuggling in the mountains is the reason. By day, the brothers Benno and Simon Schaidler are respectable citizens - by night, they are smugglers and poachers.