Sandra and Muriel are identical twins and orphaned. They look identical. One of them leads a normal life, has a job at an office and a decent sex-life. Her friend on the other hand, prefers to let her desires rule. First she gets down with a one-armed caretaker at her new flat in Paris. At weird clubs she meets up with strangers who like s/m games and she loves to debase the other girl at threesomes. Madness finally takes firm hold of her and she conspires to, so she'll be the sole heir to the enormous family fortune.