The Hangover is a 2009 comedy film directed by Todd Phillips. The movie follows the story of Phil Wenneck (Bradley Cooper), Stu Price (Ed Helms), Alan Garner (Zach Galifianakis), and Doug Billings (Justin Bartha), four friends who wake up after a wild bachelor party in Las Vegas with no memory of the night before. As they try to retrace their steps, they discover a series of hilarious and unexpected events.