Fruchtbarkeit: The young, forward-thinking doctor Dr. Maerker arrives in a small factory town and is appalled by the prevailing social conditions. The working-class families live in poor conditions and can barely feed their many children. Maerker therefore wants to give a lecture on contraception in the inn, but encounters fierce resistance from his conservative boss, Dr. Witte, who wants to prevent the lecture together with the pastor and the magistrate. Only a severe nervous fever finally persuades old Witte to side with Maerker.