In an attempt to reduce crime rates across the United States, the New Founding Fathers of America (NFFA) test a sociological theory that allows for all crimes, including murder, to be legal for a 12-hour period on Staten Island, New York. The event is marketed to the residents as the chance to release any built-up rage and anger, with the promise of compensation for anyone who stays on the island and participates in the experiment. The residents are deeply conflicted, with some embracing the concept for the financial reward or personal reasons, while others are vehemently opposed or simply want to survive the night.

As the experiment begins, the island becomes a chaotic and lawless battleground. The violence escalates quickly, with the government monitoring the anarchy from a distance and deploying additional resources to influence the outcome to ensure the experiment is deemed a success. Amidst the turmoil, a local drug lord, his ex-girlfriend community activist, and her younger brother find themselves fighting not only against purgers with malicious intent but also confronting deep-seated issues within their own community. They must navigate the dangers of the night, facing moral dilemmas and the true intentions of the NFFA while trying to protect themselves and their neighbors.