In Mexico, Coral Regina Orozco works as a nurse for a morgue and raising two young children, Carlos and Teresa. She fills her room with pictures of the French star Charles Boyer, a tender detail that hints at her longing for a glamorous or gentler life. One night, while on duty, Coral answers a lonely hearts advertisement from Nicolás Estrella [Daniel Giménez Cacho], a traveling Spanish drifter who insists he bears a resemblance to Boyer. Nicolás reads Coral’s letter and then appears at her door both in daylight and later that same night. The meeting turns intimate, but it soon sours: Nicolás steals Coral’s money and vanishes.
Coral chases Nicolás to his residence, bringing her children along, only to confront him in the act of deception. She tries to persuade him to start a life together, but he refuses, unwilling to take on the responsibilities of caring for her children. The next morning, Coral makes a drastic choice and abandons Carlos and Teresa at a convent, yet soon returns to Nicolás. She begins to see through his pattern: he seduces and robs lonely women, and she resolves to join him, even posing as his sister to stay close.
The duo heads to a bar where Juanita Norton [Julieta Egurrola], an older widow, has answered Nicolás’s ad. Juanita’s sharp tongue targets Coral’s weight, and in a fit of jealousy Coral poisons her drink with rat poison. Juanita collapses and is left to die at a train station after Nicolás’ car ride, while Coral steals her purse. A misstep for Nicolás comes when his toupee flies off in their car, leaving him furious; Coral quietly repairs it with the care of a nurse, smoothing over his humiliation.
Adopting a missionary persona, Coral and Nicolás respond to Irene Gallardo [Marisa Paredes], a devout older Spaniard, and Irene’s neighbor Sara Silberman [Rosa Furman] becomes suspicious of their sudden letters and confident performances. Sara interrogates Nicolás with pointed questions, and though he offers flimsy answers, she warns Irene about the couple’s deception. Inside Irene’s home, Nicolás charms Irene as they recite the Lord’s Prayer, and Irene hints at marriage to Nicolás.
Nicolás and Irene marry at a gravesite, a ceremony that seems to sanctify their predatory partnership. That night at a motel, Coral denounces Irene as adulterous, and while Nicolas consoles Irene, Coral bursts in and confesses she is in love with Nicolás. Irene, shocked by the idea of incest, prays aloud for forgiveness as Coral, in a violent moment, strikes Irene with a statue of Jesus and kills her. They clean the scene and bury Irene in an unmarked grave.
Their spree continues with Rebeca Sanpedro [Verónica Merchant], a widow whose husband ran a local mechanic shop. Coral suspects Rebeca is an older widow, but in truth she has a young daughter. Rebeca hires Nicolás to run the shop, and he seduces and impregnates her. When the time comes to deliver, Coral administers anticoagulants to Rebeca. As they search through Rebeca’s papers, she unexpectedly returns, and Nicolás murders her. Coral then drowns Rebeca’s daughter, sealing their shared guilt.
Facing the consequences of their crimes, Coral and Nicolás acknowledge themselves as eternal accomplices, bound by blood and by death. Nicolás phones the authorities, and the two surrender to the law. They receive the death penalty from an execution squad. On the morning of their execution, Coral whispers that it has been the “happiest day of my life” before both are shot and lie side by side in a pool of water.
> "The happiest day of my life."
