The holidays began and Pepík Janousek is playing with his friend Hadraba, whose nickname is Sun. Sun has to baby-sit his small brother in a pram and envies Pepík his nice adoptive parents because his own father beats him often. Pepík is happy - he will have soon the same surname Marek as his father and mother. Pepík is shocked when Sun tells him that Mrs Marková is pregnant. He falls from a height and ends up in hospital. Despite of all expressed love and care Pepík is afraid that the Mareks will no longer want him.

In the frontier village Vetrov boys from the children's home called Indians lead a bitter "war" with the local Símáks. Before a battle the Indians have a meeting in the sandpit with a smoke signaling. The smoke brings to the sandpit a frontier guard Tomás with a police dog Ranek. The children learn from Tomás that Rank served out and that it shall be destroyed. The nine-year old Fanda writes a letter to the "minister of the frontier guards" in which he asks to let Ranek live. To save Ranek's life he also visits the local frontier guard commander. In the end it is decided that children from the children's home may keep Ranek.

Miss Nováková reports to Major Tuma (Karel Höger) from the police about the disappearance of her roommate, the model Zuzana. Shortly afterwards, a film director named Konrád (Otomar Krejca) asks Tuma to cooperate on a new cinéma-vérité film describing the story of Zuzana's disappearance.