The Hangover is an American comedy film directed by Todd Phillips about a bachelor party in Las Vegas that goes wrong. It stars Bradley Cooper, Ed Helms, Zach Galifianakis, and Justin Bartha. In the opening scenes, one character is seen getting ready for a wedding while the other three men wake up in a strange hotel room with no memory of the previous night. Visual cues like flowers, wedding dresses, and formal costumes in one scene contrasting with scruffy looks in the other establish that the film will follow the aftermath of a wild bachelor party that has caused problems for the upcoming wedding.