The Snow Queen

"The Snow Queen" is a fairy tale by the Danish writer Hans Christian Andersen; written in 1844 and published a year later. Unlike other fairy tales based on the folklore and traditions of other nations, this story was born in the imagination of the author.
The fairy tale tells the story of Gerda and Kai's children, who are friends until one winter day, a fragment of the devil's mirror hits Kai in the eye and changes his worldview in such a way that he now perceives everything beautiful and good as ugly and bad. A good boy turns into a wayward child, angry and cruel. One day, despite the warning, the boy ties his sleigh to the winter lady's carriage and rides with her in an unknown direction. It turns out that this is the Snow Queen, the ruler of the icy land, who does not know any warm and sincere feelings. She wants to use Kai for her own purposes. Abandoned and sad, Gerda goes in search of Kai and, despite many dangers and after many adventures, eventually finds her friend and heals him. The described city, in which Kai and Gerda live, resembles Heidelberg.