The Hangover 2 picks up where the first film left off, with the Wolfpack - Phil (Bradley Cooper), Stu (Ed Helms), Alan (Zach Galifianakis), and Doug (Justin Bartha) - still reeling from the events of the first film. The group embarks on a trip to Thailand for Stu's wedding, but things quickly spiral out of control. The guys wake up after a wild night in Vegas with no memory of what happened, and it's up to them to piece together the events of the previous night.