The movie revolves around the lives of a young couple, Dr Bill and Alice Harford. One day they decide to go to one of Bill's wealthier patient's party, Victor, where Bill sees Nick Nightingale, a professional pianist. At the party, two girls also approach Bill and attempt to seduce him whilst Alice is approached by Sandor Szavost. However, he catches Victor having sex with Mandy, who overdoses and Bill manages to save her.
Later that evening, Alice questions whether Bill wanted to engage in sexual activities with the two girls who hit on him. He states that he did not want to and when she asks if he would be jealous if she engaged in activities with other men, he tells her that he has faith that women are loyal to men. However, she informs him that she had a dream where she cheated on him with a naval officer.
Bill is worried by this and so he goes to a prostitute called Domino where he begins to kiss her but this is whilst he is on the phone to Alice. He later meets Nick at a club where he informs Bill that he will be performing at an event. Bill is invited but learns he needs a costume, mask and password for the event. Bill decides to purchase a costume for the event. However, when he arrives he discovers that the event is a sexual ritual. He is questioned about a second password but he says he has forgotten the password. A woman helps him and states that he must not tell anyone what had happened there.
When Bill arrives home he sees Alice who tells him she a dream where she was having sex with the officer she had dreamt of before but that Bill had been watching whilst they performed the act and she had laughed at this. Bill goes to look for Nick the next day but is informed by the hotel staff that Nick had left with two men.
Bill then returns to the house where the sexual ritual took place but is warned off at the gate.
He later learns Mandy had died from an overdose. He then goes to Victors house where he discovers that he too is part of the orgy that took place. He reveals that Mandy was the woman who had warned Bill and had sacrificed herself for his actions. However, Victor says that Mandy was an addict anyway and would have died.
Bill leaves and goes home to tell Alice everything. The then go shopping the next day with their daughter where Alice tells him they need to do something urgently and when Bill questions what she says 'fuck'.