For four men, they vowed that a night in Vegas would be one they would never forget, but somehow they can't remember any of the bachelor party. The next morning, their hotel suite is trashed, one is missing a tooth, a tiger is in their bathroom, and they also found a baby. But what's worse: Doug the groom is missing!! Now the three groomsmen -- Phil, Stu, and Alan collect themselves and try to piece together all events of their wild night in Sin City and hopefully find Doug before returning home for the wedding...but not without some added craziness along the way. Starring Bradley Cooper, Ed Helms, & Zach Galifianakis. Directed by Todd Phillips.