LAPD sergeant Leo Barnes is the chief of security for U. S. Senator and leading U. S. presidential candidate Charlie Roan, who vows to end the Purge, having witnessed the death of her family 18 years ago, during the events of the first film. In a bid to prevent this from happening, The New Founding Fathers of America (NFFA) takes the unprecedented step of abolishing the protection afforded to government officials of ranking 10, allowing the U. S. public to target all government officials for the first time since the purge's creation. After a betrayal within the government targets her for death minutes after the Purge's commencement, Barnes must protect Roan while on the run for safety until they meet and form an alliance with some of her supporters; two shopkeepers, an EMT, and an anti-Purge rebel team headed by the wounded Stranger from the first two films, whose real name is Dante Bishop. The group are also aided by the notorious Crips gang to avoid an NFFA-loyal neo-Nazi/white supremacist paramilitary team from capturing the senator. Meanwhile, the NFFA candidate and Roan's rival, Minister Edwidge Owens, who has been set up as a candidate to maintain the status quo, leads the NFFA in committing more acts of violence during Purge night as rebels try to protect more citizens.