Karel Doležal, insurance clerk and exemplary father of a family, leaves for a business trip with his secretary Vlasta. After spending the night together, they both return home. However, thanks to a small moment of inattention, they run over the boys. Karel runs away from the scene of the crime. He won't tell anyone what happened. Then when he reads in the newspaper that the boy did not survive the accident, he begins to feel guilty. He confides in his wife about the accident, not the infidelity. Their son Jirka overhears everything. His father has always been his role model, and that's why he doesn't want to accept his guilt.

十一岁的阿历克是个性格孤僻的孩子，他白天的时候总是很想念当随船大夫的父亲，希望像父亲一样四海为家，到处去旅行……有一天，一位陌生人给阿历克带来他父亲送他的礼物。这是一包他父亲搜集的「蝶蛹」卡通画。 第二天清晨醒来，阿历克发现满屋子飞舞著五颜六色的蝴蝶，其中之一不同寻常，大大的双眼，长长的头发，她是一个「蝶仙」小精灵，阿历克称她为《乌鲁咕》，她有著神奇的力量，能使任何东西飞起来，阿历克和她形影不离，上学、睡觉都带著她。