In a small town, a brigade is working on the construction of a new cultural center. Gerhard loves Karin, the daughter of brigadier Franz, who is not thrilled with the prospective son-in-law. Under the influence of his colleague "Boxer", who wants to go to a big city with him, Gerhard neglects his crane operator course, his work and ultimately Karin too. The failed crane test infuriates him and turns him into a rioter. After quarrels on the construction site, Franz is found unconscious on the crane at night. Gerhard comes under suspicion, but the accident was the fault of "Boxer". When he tries to escape, Gerhard, who has come to his senses, is able to hold him back. Remorseful, they go to the police together. Karin is also reconciled and the wedding is to take place in the finished Kulturhaus.