This movie is in Esperanto and stars William Shatner. What more do you really need to know?
OK, so you want to know more. Incubus has a defnite European flavor, although it was made by an American director and filmed in California. Perhaps the language lends a feeling of otherness to the film, but it's quite haunting, and is beautifully filmed.
The story is about a young succubi, Kia, who lures evil men to the sea to kill them. In an attempt to win favor with her "Dark Lord" she decides to enchant and kill an honest man -- our boy Bill, playing Marc, a wounded soldier who lives with his sister. The movie's rather straightforward exploration of good vs. evil and purity vs. corruption is well done, but the pace is quite deliberate.
There's also a curse associated with the movie, which is explored in some detail in this Salon article.