The film tells the love story of two young couples. According to their social ranks, construction worker Edy is dating employee Siegi, while medical student Dieter is dating art school student Sonja. Rather unintentionally, they exchange partners. During a carnival ball, Dieter makes out with Siegi because he falls for her her fresh and happy girlish manner. Sonja coolly observes this game and sees this intermezzo as a test for their relationship. While Siegi and Dieter vacation at the sea, Sonja falls in love with Edy. Now the die seems to be cast for new constellations. But when both couples stand in front of the registrar’s office, they finally come to their senses.

Was it an act of sabotage or willful negligence? The non-party engineer Heinz Solter is suddenly arrested and accused of approving a defective pipeline that caused a half million loss to his company. At first, the case seems clear-cut for the state prosecutor, but when he probes deeper, he discovers that Solter had acted against his better judgment due to the pressure from his career-driven and authoritarian boss.

GDR border guard Gunter Rist is a young man from humble homes. During a swimming competition he meets Penny, a professor’s daughter from a good family, and they fall in love. However, their different social backgrounds get in the way of their happiness: Penny’s friends make it obvious that they are not willing to accept Gunter in their group. Although Penny takes Gunter’s side, she doubts if love can overcome all obstacles. In this state, she falls for the advances of her ex-boyfriend Bob and joins him on vacation. In the meantime, Gunter has an accident and is hospitalized. In the hospital, he meets the nurse Li who seems to be perfect for him.