Ali (Salem), is a Moroccan Gastarbeiter (guest worker) in his late thirties, and Emmi (Mira), is a 60-year-old widowed cleaning woman. They meet when Emmi ducks inside a bar, driven by the rain and drawn by the exotic Arabic music (Al Asfouryeh by Sabah) she says she has heard so often on her walk home from work. A woman in the bar (Katharina Herberg) who is part of Ali's Arabic-speaking cohort tauntingly suggests Ali ask Emmi ("the old woman") to dance, and Emmi accepts. A strange and unlikely friendship develops, then a romance and soon they are living together in Emmi's flat. Out of a professed sense of responsibility but also hopefulness, Emmi first confides in her newfound love when she goes to visit her daughter Krista (Irm Hermann) and her tyrannical son-in-law Eugen (Fassbinder himself) and announces that she is in love with Ali; Eugen thinks she is screwy and Krista as well can only think that her mother - who has been a widow for years - is fantasizing.
The first real threat to their relationship comes with a visit by the landlord's son, who has been sent on the assumption that Emmi has taken in a lodger to point out to her that sub-letting is against Emmi's tenancy agreement, and that Ali must leave within a day. Impulsively, and fearful of losing this new joy in her life, Emmi claims that she and Ali are planning to marry to alleviate this little difficulty. This changes everything for the landlord's son, the only character in the film who consistently accepts their relationship as unproblematic. After he has apologized for the misapprehension and departed, Emmi speaks to Ali with embarrassment of her having invented the idea of their marrying but, to her surprise and delight, Ali concurs that it is an excellent idea, and we next see them emerging from the civil court, married.
What follows is a bitter and noxious reaction over their relationship, revealing every character in their lives, especially every German in Emmi's former life, as being mired in prejudice against foreign workers as dirty and now castigating Emmi as a "whore." Gossipy neighbors and shop vendors treat them with contempt, fellow tenants complaining that their (already noticeably dilapidated) tenement building has now become filthy. Emmi is shunned by her coworkers, and Ali faces discrimination at every turn. When Emmi, whose first husband was a Polish worker who she married against her Hitler-loving father's wishes, invites her three grown children and son-in-law to meet her husband, they openly reject him. One of her sons smashes in her TV set in anger, her other son declares she must have lost her sanity, and her daughter and son-in-law follow them in making a rude and hasty exit, Emmi's daughter now calling her mother's apartment a "pigsty" and her mother a "whore."
Emmi's tearful despair at this ultimate rejection washes away as her bright optimist resurfaces and concludes that she and Ali should take a long vacation together to escape the discrimination, convinced that upon return, they will have been missed and will be welcomed back. After their return, they suddenly face the prospect of social acceptance but, as we quickly see, only because neighboring tenants and shopkeepers see the utility for them in keeping Emmi in their good graces, not because they have changed their prejudices, thus we witness them hypocritically masking the latter out of self-interest.
Out of longing to hang on to this resumption of her old friends' apparent renewed respect, Emmi begins to neglect Ali or to adopt some of their attitudes toward him. She becomes very "German" - more readily ordering him to do things. When co-workers visit and remark on how surprisingly clean he is and comment on his muscles, she shows him off as if he were an object. This is the trigger for Ali to exit, with our sympathy as viewers, and to seek comfort in the arms of the female bartender Barbara (Barbara Valentin), with whom he has apparently had dalliances prior to meeting Emmi. When he leaves Emmi to her friends, she attributes it to his "mood swings," and notes that it must be his "foreigner mentality", adopting the xenophobic attitudes of her friends in order to fit in. Some days later, Emmi would not cook Ali couscous or go out with him to eat couscous somewhere either, symbolizing her re-Germanification and her own new wall built up against the sensitivity to foreigners she displayed at the outset, she insists she wants him to eat German food, and generally become more German so they would fit in. We see Ali not stand up to Emmi because of the insecurities he faces as a hybrid. He has accepted the German society's mentality that he is the "lesser" man. He then turns back to the bartender, who used to cook for him, and spends the night with her. Emmi grows desperate at his being out all night and visits him at work, where he pretends he doesn't know her as his workmates make fun of her age, calling her Ali's "Moroccan grandmother."
Just when it seems as if the relationship is beyond repair, Emmi goes back to the bar to meet with Ali and has the bartender put the same song on the jukebox that led to their first-ever dance. He responds to the implicit call for reconciliation from Emmi and asks her to dance again. While dancing, Emmi emphasizes that she knows she is old and that he is free to come and go, but urges him to see that the only thing that’s important is that when they are together, they must be nice to each other. He agrees and they re-declare their love for each other and the priority they will recommit to each other. In this moment, Ali collapses in Emmi's arms from what turns out to be a burst stomach ulcer. We last see Emmi with Ali in the hospital, where the doctor tells her the illness is common among migrants because of the stress they face in everyday life due to prejudice; the doctor adds that Ali will have surgery to remove the ulcer, but will probably be back in 6 months with another ulcer. Emmi declares that she will do everything in her power to reduce that stress and, as the film ends, she is at his bedside, holding Ali's hand.