Cleodegaria "Cleo" Gutiérrez is an indigenous live-in maid in a middle-class household in the Colonia Roma neighborhood of Mexico City. The family's matriarch, Sofía, her husband, Antonio, grandmother Teresa, their four young children, and another maid, Adela, also live in the house. Antonio, a doctor, leaves for a conference in Quebec. It becomes clear that Sofía and Antonio's marriage is strained. After returning briefly, Antonio leaves again, saying he is going to Quebec for a few weeks.
Cleo and Adela go out to the cinema with their boyfriends, Fermín and Ramón. However, Cleo and Fermín decide to rent a room instead. Fermín shows off his martial-arts skill using the shower curtain rod as a pole. Later, at the cinema, Cleo tells Fermín that she thinks she is pregnant. As the film—La Grande Vadrouille—is about to end, Fermín says he needs to use the bathroom and will be back, but then does not return and is nowhere to be found. Cleo reveals the same concern to Sofía, who takes her to get checked at the hospital where Antonio works. A doctor there confirms her pregnancy.
Sofía takes Cleo, Adela, and her children to a family friend's hacienda for New Year's. Both the landowners and the workers mention recent tensions over land in the area. During the celebrations, a fire erupts in the forest. Everyone helps extinguish it while a man counts down the remaining seconds of 1970 before singing a Norwegian lullaby.
Kinder Condesa at 105 Tlaxcala street, Colonia Roma
Back in the city, Cleo accompanies the children and their grandmother to a cinema to watch Marooned. They see Antonio rush out with a young woman—a fact Sofía tries to conceal from the children, but which her second son later learns of by eavesdropping. She asks him to not tell his siblings. Through Adela's boyfriend, Cleo finds Fermín at an outdoor martial-arts class. During the class, of all those watching, only Cleo is able to balance with eyes closed in imitation of a blindfolded instructor who is performing a pose much like a vriksasana. Her boyfriend refuses to acknowledge that the baby is his, and threatens to beat her and their child if they try to find him again.
Ribera de San Cosme avenue and Lauro Aguirre street, where the Corpus Christi massacre
occurred. The building that was the furniture store and school in the film is now a gym.
With the baby almost due, Teresa takes Cleo shopping for a crib. On the way, they see students gathering to protest in the streets; these turn deadly because of police clubbings, while bands of roving youths—implied to be the paramilitary group Los Halcones (The Hawks)—randomly shoot at protesters. When a wounded man and a woman run into the store trying to hide, several youths find the man and shoot him dead. Another gunman, who points a gun at Cleo, turns out to be Fermín; he glares at her momentarily before running off.
Cleo's water breaks. Cleo, Teresa, and their driver try to get to the hospital but are stuck in traffic amid the violent protests. Antonio comes by to reassure Cleo, who is now in the delivery room, but makes an excuse to avoid staying. Hearing no heartbeat in Cleo's womb, the doctors take her into surgery, where they deliver a stillborn girl. Multiple attempts to resuscitate the baby fail.
After a drunken attempt to park the car in the family's narrow garage, Sofía buys a narrower car, but plans a final trip in the old car for a family holiday to the beaches at Tuxpan. She takes Cleo as well, to help her cope with her loss. Sofía tells the children that she and their father are separated, and that the holiday was so their father can collect his belongings from their home. At the beach, the two middle children are almost carried off by a strong current. Cleo wades in to save them, even though she doesn't know how to swim. As Sofía and the children affirm their love for Cleo for such selfless devotion, she breaks down and reveals that she had not wanted her baby to be born. They return home to Roma to find the house reorganised. Cleo prepares a load of washing, telling Adela they have much to talk about. Cleo climbs ladders to the rooftop with the clothes to wash.