What if, one night a year, all crime, including murder, was legal? That's the premise of an incredibly successful horror movie franchise set in the not-so-distant dystopian future. The idea of The Purge is: Let people blow off steam, and crime rates will go down. The fourth Purge installment — The First Purge — opens July 4.
The Purge films have, on average, made almost 2,000 percent of their budget at the worldwide box office. What is it about these stories of society-run-amok that keeps audiences coming back?