Once upon a time there was a commoner who married a king. Her name was Bodil, and she was also a witch. This was a dark and hidden secret that Bodil revealed to no one. The practice of witchcraft was strictly forbidden in the kingdom—and punishable by death. But witches cannot get pregnant, not by natural means, and the king wants a child, an heir to the throne. He grows suspicious of his young queen, and Bodil knows that her life is in danger.
To save herself, she journeys alone to a magical forest, the realm of the all-mighty Elf Queen. The Elf Queen, with her supernatural powers, grants Bodil a son, but not without a cost: the child must be returned to the Elf Queen on his eighteenth birthday. Bodil accepts this agreement, convincing herself that she will never love him.

The Elf Queen is the prequel to a tv seres with the same title, currently in development.