Sadomasochism and Nazisploitation, with a young and sultry Charlotte Rampling and a deep and brutal Dirk Bogarde; one of the few movies I've heard of that has been directed by a woman, and a fantastic film. It is very brave, and highly artistic.
The theme of it comes from a research conducted on survivors of Nazi concentration camps, in particular women, who tend to visit and even vacation around the sites of the camps they were in. The psychology involving this film is therefore from the start pretty convoluted.