Beyond the river lies the Dark Wood. Agnieszka loves her village and the valley in which she lives. But beyond the silver river in the Dark Wood lurks an evil power. Only the dragon, a sorcerer, can keep it under control. For this, he demands a girl to serve him every ten years. The time of the choosing is approaching, and everyone knows that it will fall on Kasia, Agnieszka's best friend. She is beautiful, graceful, brave - the opposite of Agnieszka. But when the dragon comes, he does not choose Kasia; he chooses Agnieszka instead.