Dailies | Ethan Hawke, Lena Headey Brace for Legalized Killing Spree in ‘The Purge’ Trailer (Video)

"The Purge" is set in a futuristic United States in which all crime is legal once a year for 12 hours

Ethan Hawke and Lena Headey prepare to protect their children in the confines of their secure home during a legalized killing spree in the first trailer for "The Purge."

The thriller, produced by Jason Blum (“Paranormal Activity," "Sinister") and Michael Bay's Platinum Dunes (“The Texas Chainsaw Massacre”), is set in a futuristic United States that has reduced unemployment to just one percent and dramatically lowered crime statistics. But utopias are rarely perfect and this version of the U.S. is no different.

Also read: Universal Sets May 2013 Release Date for 'The Purge'

One night every year, the government sanctions a 12-hour free-for-all crime spree in order to purge society of its killer instinct.

"Tonight allows people a release," Hawke explains to his children. "For all the hatred and violence that they keep up inside them."

Although Hawke's family refrains from participating, the violence comes to them when their son lets a stranger into their home and his masked attackers follow, threatening to kill everyone unless the family gives up the target.

We'll find out how it all pans out when Universal releases the home-invasion horror on May 31. Until then, watch the trailer to find out what happens when murder is legalized: