In Xochimilco 1909, María Candelaria and Lorenzo Rafael long for getting married but the odds are against them. Maria Candelaria is segregated for being a prostitute's child and the couple faces the greed of Mr. Damian, the town's shop owner who secretly desires Maria. When Maria falls sick with Malaria, Lorenzo Rafael steals a quinine bottle from Damian's shop, unleashing tragedy for the lovers.
- The film follows Mexican indigenous lovers Maria Candelaria (Dolores Del Rio) and Lorenzo Rafael (Pedro Armendariz). In the opening scene, a respected elderly painter is asked by an art student to see a nude painting he has never displayed publicly. He reluctantly agrees, but cryptically states that the painting caused a scandal which resulted in "a tragedy". He begins to narrate the story. Maria Candelaria is the beautiful indigenous daughter of a deceased prostitute. Even though she herself is childishly innocent, for her mother's sins, she is ostracized by the entire village. The cruel and horrific treachery of the townspeople is juxtaposed both by the incredible beauty of the idyllic aquaculture landscape of the area outside Xochimilco, Mexico in the very early 1900s, and the beautiful and innocent unconditional love of another young indigenous man, Lorenzo Rafael. The rich tribal chieftain and monopoly storekeeper of the indigenous village, Don David, is covetous of Maria Candelaria, and wants to use the fact that she owes him a modest sum of money to force himself on her, by using his influence with the townspeople to block her from being able to raise the money she owes by selling her flowers in the town marketplace. When she and Lorenzo Rafael are forced to sell flowers and vegetables in the nearby Xochimilco marketplace, Maria Candelaria is seen by the then young painter from the opening scene. He tells her that he wants to use her as a model for his paintings of indigenous themes, but the young woman demurs due to her provincial values. The couple dreams about getting married by a friendly priest in the village after Maria's piglet grows up, so she can sell it for money to purchase a wedding dress. One morning, Don David goes to her mini flower farm and shoots and kills Maria's piglet. On a moonlight canal boat outing with Lorenzo Rafael, Maria Candelaria is bitten by a mosquito and later contracts malaria. Only Don David carries the quinine that the Mexican government has entrusted to him for the care of the whole village. When she gets gravely sick, Lorenzo Rafael tries to purchase the quinine she needs to save her life from Don David, only to have him threaten to kill him. In desperation, Lorenzo later breaks into Don David's company store and steals the quinine and a wedding dress. The painter learns of Maria Candelaria's illness and with the help of the friendly priest, brings a doctor to cure her. Maria Candelaria and Lorenzo Rafael are then married by the priest. Maria now feels obliged to pose for the painter who helped save her life. When the painter expresses his wish to paint her in the nude, she refuses in horror to disrobe for the painting and runs away, and the painter uses another model as a body double. Meanwhile, Lorenzo Rafael is arrested and sentenced to jail for the theft from Don David. On an errand to Xochimilco, one of the women from the town goes to the painter's house and sees the finished nude painting with Maria Candelaria's face and tells of the disgrace to the whole village. The townspeople then pursue her through the streets and stone her to death, and she dies in the arms of the escaped Lorenzo Rafael.