Undine

Undine is a novel by Friedrich de la Motte Fouqué concerning Undine, a water spirit who marries a Knight named Huldbrand in order to gain a soul. It is an early German romance, which has been translated into English and other languages. The novel served as inspiration for two operas in the romantic style by Ernst Theodor Amadeus Hoffmann and Albert Lortzing, respectively, and two ballets: the nineteenth century Ondine and the twentieth century Undine. An edition of the book was illustrated by Arthur Rackham. In The Fantastic Imagination, George MacDonald writes, "Were I asked, what is a fairytale? I should reply, Read Undine: that is a fairytale ... of all fairytales I know, I think Undine the most beautiful." (Summary from Wikipedia)