In the first days of the summer holidays, Petyo, Elka, Maya and their classmates go for a swim and a bit of frisking and dancing to the mill on the river. Petyo throws a bomb into the pond to catch fish. Elka reports it to the high-school headmaster principal. Petyo and Elka are mutually attracted in their first love, but they do not dare to reveal their feeling for each other. The boys blame Petyo for covering up what they think is Elka's betrayal. Petyo starts dating with Maya, who has long fancied him. Maya accuses Elka of what she calls "a foul deed behind her friend's back". Elka tries to defend herself but, seeing that she cannot make her point, she walks away, alone, down by the riverside.