It's a movie about lust and desire and the various forms it takes. I know that some people want to attach some higher meaning to it, such as the evil in men's hearts, etc., but it's it's basically about the various forms of lust/desire that people have in their hearts. The character, Francis the musician, with his screwed-up upbringing is a bit of a schizoid, and his desire for Halley the schoolteacher reflects one side of his personality, but his desire for less savory things (which I won't spoil) reflects the other side of his personality. Even the character of Morris the lounge owner, Francis' boss, reflects a homosexual desire for Francis.
I have to say, Katja Riemann, as Halley, is extremely sexy. She was an ideal choice for the older woman role. Teamed up with Zach Bennett as Francis, there was a definite chemistry there. I didn't realize that Zach Bennett was so young either. At the time of filming Bennett must have been 20 years old, while Katja must have been 37.