Just two days before his marriage with Tracy Garner, Doug Billings, in the company of two friends: Phil Wenneck and Stu Price; and Tracys eccentric brother, Alan, head out to party in Vegas. Driving his fathers Mercedez, they rent a pricey villa at Caesars and head for the rooftop to have a good time. Three of them later wake up with a hangover, unable to recollect what exactly happened. With the villa in a wreck, turned upside down, they find that they have a baby in the closet, a grown tiger in the bathroom, Stu has a missing tooth and a hooker for a bride, and Doug is missing. Hilarious chaos results as the trio head out to retrace their steps, find out that occurred in order to try and locate Doug, and bring him home in one piece before the wedding.