An ambulance races through the streets of Vienna in the early hours of the morning, containing a psychiatrist, Alex Linden, and the unconscious body of his friend, Milena Flaherty. Upon arriving, Alex informs the hospital that he received a call from Milena at 1.00am saying that she had attempted suicide. He claims he found her comatose in her apartment and immediately called an ambulance.
While emergency procedures are performed upon Milena, who has washed an overdose of prescription drugs down with alcohol, Alex recalls their passionate affair.
They first met at a party, where they found a mutual attraction in each other's ambivalent personalities. Milena is impulsive and unpredictable, while Alex is rather cold and clinical towards other people. They meet at a café, travel around Vienna and make love, after which Alex reads poetry.
As the relationship becomes more intense, Alex becomes suspicious of Milena's activities while they are apart and increasingly jealous of her flirtatiousness towards other men, some of whom she seems to know very closely. Milena reacts to this in a defensive and hostile manner, insisting she is single, and takes refuge in heavy drinking. Alex is also perplexed by her regular trips across the border to Czechoslovakia, where she claims to be seeing her brother.
Alex is asked to do some personality profiles for the US Government of prominent Czech citizens, one of whom is Stefan Vognic. Stefan's file indicates that he is married to MIlena. She says it is unimportant, but Alex needles her and begins to have violent fantasies, in which he forces her to tell him which of her men she most cares about. Alex becomes obsessive about what he sees as Milena's secrets and starts to follow her around Vienna, where he sees her with another man. He goes to the Czech Embassy to ask about the possibility of a divorce, but he doesn't receive any help and Milena is angry that he has gone without her.
When Milena tidies up her apartment, specifically to please Alex, he is initially impressed, but when his sexual advances are spurned, he gets annoyed and leaves. Milena follows him to the stairs and angrily offers herself to him. The sex is violent and unfulfilling and Milena returns to the apartment to undo her pointless tidying.
A trip to Morocco indicates how the relationship has broken down. His subsequent offer of marriage is turned down by Milena, who values her freedom. Alex phones Stefan to ask him for advice about how to deal with Milena, but Stefan is unconcerned, casually saying that Milena will soon get bored and return to Czechoslovakia.
The situation deteriorates and Alex becomes cold towards Milena. She is convinced that he wants to possess her, but only on his own terms, and when he comes round in response to a tearful phone call, he finds her drunk and made up as a corpse. She starts an argument, throwing bottles at him out of the window as he walks away from her apartment.
The present: at the hospital, Inspector Netusil, assigned to the case, interrogates Alex about his relationship with Milena. He is convinced that Alex is lying about the timing, believing that he must have received the phone call at least two hours earlier than he claims. This would leave a long gap between Alex arriving at Milena's apartment and him phoning for the ambulance. Netusil takes Alex to Milena's apartment and, observing the disorder around the bed and torn clothes on the floor, accuses Alex of the crime of ravishment.
The past: Alex arrives to find Milena half-conscious on the floor, harangues her about her other lovers and pulls the phone out of the socket. Denying her any outside help, he cuts off her clothes and rapes her while she lies unconscious.
Inspector Netusil has guessed the truth and, fascinated despite himself, tries to persuade Alex to confess, but Alex refuses.
Stefan arrives and reveals that Milena has survived and is out of danger. Alex returns to America where, some time later, he sees Milena getting out of a taxi. He shouts to her but she ignores him.
