The orphan boy Heintje lives with his aunt, who neglects him badly. He much prefers to be with the racing stable owner Teichmann and his horses. While Teichmann is in Switzerland, Heintje is put in a youth home by his aunt, but manages to escape secretly and makes his way to his fatherly friend. On the journey he melts all adult hearts with his singing, but there is still danger: a gang of smugglers abuses him as an unsuspecting courier, and Hanna, a woman from the youth welfare office, is supposed to ship him back to the home. Luckily, she turns out to be Teichmann's former girlfriend, with whom she promptly gets back together. Together they adopt Heintje.