Charming bon vivant Rudolf is convinced that infidelity is the basis for a happy marriage, since, after all, a woman does not want to be bored with her partner.

In the former Czechoslovakia, 1950s, police captain Hakl investigates a jewelery robbery. An opened safe deposit leads to a known burglar. What seems an easy case soon starts to tangle. When he is called off the case, he continues on his own. The investigation leads him onto thin ice. Can he beat a stronger enemy and save his family and his own life?