Undercover U.S. agent Bill Wilson makes the bust of his career taking down a cartel leader. Hiding the evidence in his home exposes his family to a brutal targeting on the night of the annual Purge, the deadliest night of the year.
As a group of wealthy friends decide to celebrate the launch of their tech company with a trip to Cabo, they get more than they bargained for when a mysterious man offers to escort them on his family's vintage cruise ship. Once on board, the family's ulterior motives become clear and the friends are hunted one by one. With everyone stranded at sea with little hope and no connection to the outside world, a Coast Guard team engages for a final deadly confrontation.