La Motte Fouqué, Friedrich Heinrich Karl, Baron de. Undine.
An anonymous translation at Project Gutenberg
Translated by Fanny Elizabeth Bunnett, at Project Gutenberg
"Most artistic of all the continental weird tales is the German classic Undine (1814), by Friedrich Heinrich Karl, Baron de la Motte Fouqué. In this story of a water-spirit who married a mortal and gained a human soul there is a delicate fineness of craftsmanship which makes it notable in any department of literature, and an easy naturalness which places it close to the genuine folk-myth. It is, in fact, derived from a tale told by the Renaissance physician and alchemist Paracelsus in his Treatise on Elemental Sprites.
"Undine, daughter of a powerful water-prince, was exchanged by her father as a small child for a fisherman's daughter, in order that she might acquire a soul by wedding a human being. Meeting the noble youth Huldbrand at the cottage of her fosterfather by the sea at the edge of a haunted wood, she soon marries him, and accompanies him to his ancestral castle of Ringstetten. Huldbrand, however, eventually wearies of his wife's supernatural affiliations, and especially of the appearances of her uncle, the malicious woodland waterfall-spirit Kuhleborn; a weariness increased by his growing affection for Bertalda, who turns out to be the fisherman's child for whom Undine was changed. At length, on a voyage down the Danube, he is provoked by some innocent act of his devoted wife to utter the angry words which consign her back to her supernatural element; from which she can, by the laws of her species, return only once -- to kill him, whether she will of no, if ever he prove unfaithful to her memory. Later, when Huldbrand is about to be married to Bertalda, Undine returns for her sad duty, and bears his life away in tears. When he is buried among his fathers in the village churchyard a veiled, snow-white female figure appears among the mourners, but after the prayer is seen no more. In her place is seen a little silver spring, which murmurs its way almost completely around the new grave, and empties into a neighboring lake. The villagers show it to this day, and say that Undine and her Huldbrand are thus united in death. Many passages and atmospheric touches in this tale reveal Fouqué as an accomplished artist in the field of the macabre; especially the descriptions of the haunted wood with its gigantic snow-white man and various unnamed terrors, which occur early in the narrative." (Supernatural Horror in Literature, VI. Spectral Literature on the Continent)