Undine is a slender novella, or rather, a longish fairy-tale in the ninteenth-century romantic tradition of the Brothers Grimm and Hans Christian Andersen. The afterword seems to indicate that it was an inspiration for Andersen's "The Little Mermaid," and that may well be. Undine appeared in 1811. (I was constantly struck by how much the language - which is to say, German - has changed since then, though one gets accustomed to the differences quickly enough.) It is the story of a water spirit, an elemental creature without a soul, mischievous, inconstant, childish. But she marries a knight, and through their union acquires a soul, becoming good and selfless. Two forces conspire against the happiness of Undine and her knight: her uncle Kühlborn and the lady for the love of whom the knight had gone into the forest where he found Undine. There is, of course, a magical taboo that is broken, with tragic consequences. Like "The Little Mermaid," the story is a bittersweet version of the Pygmalion story.