Chris and his girlfriend Rose go upstate to visit her parents for the weekend. At first, Chris reads the family's overly accommodating behavior as nervous attempts to deal with their daughter's interracial relationship, but as the weekend progresses, a series of increasingly disturbing discoveries lead him to a truth that he never could have imagined.
Colorado Springs, late 1970s. Ron Stallworth, an African American police officer, and Flip Zimmerman, his Jewish colleague, run an undercover operation to infiltrate the Ku Klux Klan.
All the rules are broken as a sect of lawless marauders decides that the annual Purge does not stop at daybreak and instead should never end as they chase a group of immigrants who they want to punish because of their harsh historical past.