The film follows the mixed-breed dog Hagen, who moves with his 13-year old guardian Lili to the home of her estranged father. Unwilling to pay a harsh “mongrel” fine, imposed by the Hungarian government, Lili’s father wishes Hagen out of the way. Lili rebels and takes Hagen with her to music class. The music teacher, annoyed by the disruption, orders Lili to move the dog out. Lili does as she is told, but she defiantly leaves, too. When Lili’s father abandons Hagen on the side of the road, Hagen chases their car, but is unable to catch up with them.