In a dystopian near future where the United States endures its annual 12-hour Purge—a government-sanctioned event during which all crimes, including murder, are legal—citizens prepare for the mayhem, and many vulnerable individuals seek sanctuary. The narrative follows Adela and her husband Juan, who fled a drug cartel in Mexico and are now working for the wealthy Tucker family in Texas. The Purge night arrives and while the wealthy secure themselves in fortified sanctuaries, Adela, Juan, and other marginalized community members brace themselves in hideouts, hoping to survive the carnage.

As dawn breaks, signaling the end of the Purge, the violence unexpectedly continues. A group of Purgers, dissatisfied with the government-imposed time limit, have decided to enact a "Forever Purge" to eliminate those they deem unworthy to be American citizens. This ongoing chaos forces people from all walks of life, including Adela, Juan, and the Tuckers, to band together in a fight for survival. They embark on a perilous journey across Texas, looking for a safe haven from the relentless attacks of the marauding gangs who refuse to cease their assault, challenging not only their will to survive but the very fabric of society.