The Hangover, Todd Phillips’ return to fratastic form after the disappointing School for Scoundrels, marks itself as an aesthetic step up for the Old School director right from the get go. With moody, pensive music playing on the soundtrack, the opening credits play out over a montage of Las Vegas By Day — giant cranes breaking the skyline of dull towers, Godzilla-size advertisements for “talent” like Marie Osmond baking in the sun — fading into the more palatable, glittery, and familiar images of Vegas By Night. This tells us right away that The Hangover means to say something about the contradictions of the city in which its set, and particularly the contrast between the Vegas myth of endless nights of full-on debauchery, and days spent nursing head-splitting regret at all-you-can-eat buffets. But Sin City presents Donnie and Marie is only the half of it: more importantly for The Hangover’s purposes, Vegas is a city constantly in construction, creating and erasing its own totally manufactured history,  a vacation spot paradoxically designed to provide inspiration for amateur photographers, which simultaneously boasts of its ability to send the same tourists home without memories that they could relate in mixed company.

In other words: the whole goal of the contemporary trip to Vegas is to come home with a digital camera full of evidence that you had a bunch of fun that you can’t recollect and certainly are not going to talk about. So when Phil (Bradley Cooper) Stu (Ed Helms) and Alan (Zack Galifinakis) wake up in their suite at Caesar’s the morning after Doug’s (Justin Bartha) bachelor party to find that their room is trashed and they’ve been left to care for a wandering chicken, a live tiger and a mysterious baby, the initial assumption is that this detritus is Vegas business as usual. Why can’t they remember anything that happened the night before? As Phil puts it, “Because we obviously had a great fucking time.” So great that the groom has gone missing.

So begins a detective noir in the unforgiving desert sun, as the three boys follow a trail of clues in the hopes of piecing together the details of their mystery evening, and getting the groom to the wedding in one piece. As the film moves from one setpiece to the next and the boys suffer at the hands of one hybrid stereotype after another (A townie drug dealer! An effeminate Asian gangster!), the film’s aesthetic foreshadowing begins to sync up with its “some guys just can’t handle Vegas” tagline. The Hangover reveals itself as a revenge fantasy, with Mike Tyson delivering a literal punchline, in which the “real” Vegas rises up against the entitled weekend warriors who come to town talking like they’re looking for trouble, but who really just want to get drunk, get a lap dance, and get home before incurring the wrath of their wives. Sadly, even this class-based revolution lacks imagination. Beyond a certain glee produced by the punishment of douchebags, what happens and what’s revealed on this lengthy fact-finding mission is disappointingly tame when it’s not borderline cliche. Nebbishy dentist Stu wakes up married to stripper/hooker/single mom Jade? Crazy!

That Jade is played by Heather Graham, however, is of some interest: Cooper and Helms seem to be playing extreme versions of the now-archtypical Vegas tourists created twelve years go by Vince Vaughn and Jon Favreau in Swingers, a film in which Graham embodied a sweet rescue in contrast to the sleaze of Vegas itself and the dating scene in general. That she’s essentially performing the same function here — ie: her undemanding amenability is a salve to an emasculated man’s pain ––  but from within a character that also fucks guys for money, surely says … something. At the very least, it’s indicative of The Hangover’s embrace of the restorative power of debauchery: the boys travel,  Inferno-style, through hell to become better people. Vegas saves.

Which is interesting and all, but this is still ostensibly a comedy. The best joke in The Hangover might be its most inside one: as the crew drives into Vegas, Kanye West’s “Can’t Tell Me Nothing” plays on the sound track; it’s surely a nod to the video for the song, which features Galifinakis inexplicably lipsyncing in a field with Will Oldman. The discordance that makes that clip so phenomenally entertaining that it borders on profound seems to be a Galifinakis speciality, and that it follows him into the Hangover is a godsend; he’s the film’s only source of genuine surprise.

Maybe more importantly, he’s the only actor working hard enough to transcend  type. As written, the character is a pretty standard issue weirdo hanger on who proves himself as a worthy member of the crew by saving the day doing something only he can do. But long before he’s put to work in a triumphant montage, Galifinakis proves himself as the story’s real protagonist, the audience surrogate who, no matter how bad the on-screen predicament gets, is unendingly grateful just to be along for the ride. If The Hangover were just a movie about how Las Vegas enacts its revenge on the douchebag tourists who seek to conquer it, it would be as watchable as it is. It’s only thanks to Galifinakis that we don’t root for the house to win.