a meeting of men to choose someone, a combine machine

A sheriff investigating the disappearance of a young girl from a small island discovers there's a larger mystery to solve among the island's secretive, neo-pagan community.

Police sergeant Neil Howie is called to an island village in search of a missing girl whom the locals claim never existed. Stranger still, however, are the rituals that take place there.

One night per year, the government sanctions a 12-hour period in which citizens can commit any crime they wish -- including murder -- without fear of punishment or imprisonment. Leo, a sergeant who lost his son, plans a vigilante mission of revenge during the mayhem. However, instead of a death-dealing avenger, he becomes the unexpected protector of four innocent strangers who desperately need his help if they are to survive the night.

Two years after choosing not to kill the man who killed his son, former police sergeant Leo Barnes has become head of security for Senator Charlene Roan, the front runner in the next Presidential election due to her vow to eliminate the Purge. On the night of what should be the final Purge, a betrayal from within the government forces Barnes and Roan out onto the street where they must fight to survive the night.