The movie begins in a factory in France, where workers demand justice from an arrogant owner after an accident injures many. Chaos ensues, and Michal, one of the workers, is arrested while trying to confront the police. Months later, he’s released but under restrictions, living with his bedridden girlfriend, Karin, while their daughter Selma struggles with the fallout of their divorce.

As acid rain caused by pollution begins to affect the area, Michal and Elice (Selma's mother) grow increasingly concerned for Selma's safety. After a chaotic attempt to retrieve her from school, the family faces a series of terrifying incidents as they try to escape the devastation caused by the rain, which results in casualties and destruction.

During their harrowing journey, Elice tragically dies during a stampede on a collapsing bridge. Michal and Selma continue to flee, facing challenges like finding shelter and dealing with the toxic environment. They eventually find refuge with a woman named Deborah, but the house begins to fall apart during another rainstorm.

In the end, after a series of intense struggles, Michal saves Selma from a sinking structure but suffers severe injuries. They are eventually rescued by the military, but Selma learns of Karin's death and chooses to keep it from Michal for now. The film concludes with Selma finding comfort in her father's arms as they recover together.