On the day Andrzej graduates from police academy and receives his officer's stripes, his father, a senior police officer, is murdered. Andrzej, assigned to the investigative brigade, tries to find the murderer, who turns out to be a member of an international gang of counterfeiters. The mysterious ringleader resorts to the help of Janina, an innocent girl who has nothing to do with the criminals. He blackmails her into pretending to be in love with Andrzej and extracting the necessary information from him. But the girl falls in love for real, and he falls in love with her too...