Film review: The Purge (15) In this future-set home-invasion thriller "Safe night" is the new "Goodnight." The year is 2022, and crime is way down thanks to "The Purge," a 12-hour window in which all criminal activity, including murder, is legal. Family man Ethan Hawke and his wife (Lena Headey) believe themselves safe in their de luxe locked-down homestead - he's a security-systems executive - until their young son allows a homeless man, tattered and bloodied, into the house. Next thing a gang of masked vigilantes led by a preppie psychopath is baying for blood outside their front door. James DeMonaco is fine with the stalking and killing part - it's pretty strong meat, with scenes of torture - but less convincing with the rhetoric of salvation. Upright American citizens claiming to be "cleansed" of hatred by murdering looks foolish unless it's being played as satire - and this ain't satire.