The investigation of the melon affair, to remain undisclosed for thirty years, is led by Major Piroska Szabó, the secret girlfriend of Mr. Kálmán, the boss, with a charge against the policemen Lajos Endúros and Richard Wagner. Sitting on the terrace of their favourite snack bar, the two policemen, along with Sergeant-Major Badár, take an oath not to testify against each other, and to mislead the authorities by giving false evidence.