A stunning explosion of a marble Greek bas-relief unveils Afro-Brazilian men who are joyfully dancing the samba to the rhythmic beats of drums in a favela. Enter Eurydice, who arrives in the vibrant city of Rio de Janeiro and boards a trolley driven by Orfeu. As a newcomer, she travels to the end of the line, where Orfeu introduces her to Hermes, the station guard, who provides her with directions to her cousin, Serafina's home.
Although engaged to Mira, Orfeu feels indifferent about their impending marriage. The couple visits the courthouse to obtain a marriage license. When the clerk whimsically remarks about Orfeu's name, suggesting a mix-up with Eurydice, it irritates Mira. Following this incident, Mira insists on acquiring an engagement ring. Despite having just received his paycheck, Orfeu is more inclined to spend his money retrieving his guitar from the pawn shop for the upcoming Carnival. Ultimately, Mira offers to lend him the funds for the ring.
Upon returning home, Orfeu discovers that Eurydice is staying next door with Serafina. Eurydice has fled to Rio to escape a menacing stranger whom she fears may want to harm her. This figure, embodying Death in a stylized skeleton outfit, locates her, but Orfeu heroically chases him away. Love blossoms between Orfeu and Eurydice, yet their romance is fraught with peril, as they evade both Mira and Death. When Serafina’s sailor boyfriend, Chico, arrives, Orfeu kindly offers Eurydice the chance to sleep in his home while he opts for the hammock outside. Eurydice invites him in, and they share an intimate night together.
As members of a local samba school participating in Carnival, Orfeu, Mira, and Serafina are key players in the festivities. Serafina schemes to have Eurydice don her Queen of the Night costume, allowing her to spend more time with Chico. Under the disguise of a veil, only Orfeu knows of this ruse. During the parade, he dances with Eurydice instead of Mira, amplifying the tension.
However, Mira eventually spots Serafina in the crowd and tears away Eurydice's veil. This act forces Eurydice into a frantic escape from both Mira and Death. In a climactic moment at Orfeu's trolley station, she hangs perilously from a power line to evade him, but tragic fate strikes as Orfeu accidentally electrocutes her while activating the power. Death ominously declares, > "Now she's mine," before rendering Orfeu unconscious.
In despair, Orfeu seeks Eurydice at the Office of Missing Persons, despite Hermes confirming her death. The desolate building, shrouded in shadows, houses only a janitor tidying up. Understanding Orfeu's anguish, the janitor leads him down a dark spiral staircase—an allusion to the mythical Orpheus’s journey into the underworld—towards a Macumba ritual, crucial to the Afro-Brazilian Candomblé faith.
At the gate, they encounter a guard dog named Cerberus. During the ritual, the janitor instructs Orfeu to sing to summon his beloved. Eurydice's spirit possesses an old woman, conversing with Orfeu. He yearns to gaze upon her, but Eurydice warns him not to do so or he will lose her forever. Overcome with longing, he glances back, sees the old woman, and Eurydice's spirit vanishes, echoing the fate as told in Greek mythology.
Grieving profoundly, Orfeu retrieves Eurydice’s body from the morgue, cradling her lifeless form as he traverses the city towards his home, where he finds his shack ablaze. Filled with vengeance, Mira hurls a stone that strikes his head, sending him tumbling off a cliff—still holding Eurydice close.
Two children, Benedito and Zeca, who have been closely following Orfeu’s journey, are captivated by his claim that his guitar playing brings forth the sun each day. After his tragic death, Benedito urges Zeca to pick up the guitar and play. Zeca complies, and from his strumming, the sun emerges. A little girl presents Zeca with a solitary flower, and the trio dances, embodying the hope and rebirth that follows loss.
