A gun-shot gumshoe stumbles upon a secluded villa inhabited by a certifiably insane, incestuous, sadomasochistic mother-daughter couple. The daughter straps him down and administers high electric voltage through his forehead, while the mother rides his convulsing pelvis and then proceeds to cool him down with a golden shower. Then things get weird...
I won't give you a play by play of this sick and twisted piece of European cinema. If you're simply interested in seeing some of the most extreme S&M stuff ever put on cinema, then by all means see it. However, if you're looking for a little bit more than that, then you might be left wondering "what was the point of all this?" Interesting themes are developed in this film, such as the omnipresence of the absentee father who is the root cause of the womens' insanity, the gumshoe's Pygmalion-like stubborn attempt to "rescue" the girl from her predicament, the mother-daughter rivalry with the inevitable matricide, death as liberation from the misery of life. But none of these themes are adequately fleshed out, making the plot feel disjointed and incomplete.
Some of the scenes in Singapore Sling would make Marquis de Sade proud, but Nikolaidis' storytelling would make Pasolini wince. Still, the movie is competently directed and photographed and overall is worth a look. Just don't eat anything before you watch it. You'll thank me later.