Part II, technically, but what's the difference?
The Hangover Part II (Warner Bros.) isn't so much a sequel to The Hangover as a slightly blurred copy. Directed, like the wildly successful first film, by Todd Phillips, it airlifts the original characters, premise, and story structure out of Vegas and plonks them down in Bangkok in near-identical form, save for a few instances of ante-upping.
Several years after their Vegas bachelor party turned into a 48-hour nightmare involving drug-laced drinks, a prostitute's missing baby, and near-fatal encounters with both Mike Tyson and his pet tiger, the four friends meet again in Thailand for the wedding of Stu (Ed Helms), a seemingly straight-laced dentist, to Lauren (Jamie Chung), a nice, pretty Thai girl. (I'd provide a more precise description of Lauren, but that's all the movie gives me to work with: She's Thai, pretty, and nice, or, as one of Stu's buddies put it, "an angel with a solid rack.")
Besides the bridegroom, Stu, the gang includes Phil (Bradley Cooper), a handsome family man with a taste for debauchery; Doug (Justin Bartha), a bland foil who hangs around waiting to take expository phone calls; and Alan (Zach Galifianakis), a socially underdeveloped weirdo who explains his living situation as follows: "I'm a stay-at-home son." Once again, Alan has been invited along only out of grudging politeness; the other guys are creeped out by his overeager insistence that their shared experience in Vegas has bonded them forever.
The night before the wedding, for reasons that aren't revealed until much later, an innocent round of beers around a beachside fire leads to another rabbit hole of amnesia and poor decision-making. The boys wake up the next morning in a grimy Bangkok hotel room amid various clues to the previous evening's excesses: There's a clothed monkey, a severed finger in a bowl of melted ice, and a coked-up Asian gangster (Ken Jeong) who remembers them from Vegas. Worst of all, one of their cohort—the bride's naive 17-year-old brother Teddy (Mason Lee, son of the director Ang Lee) has gone missing.
The rest of the movie spirals chaotically yet formulaically into the depths of the Bangkok underworld. Tattoo parlors are visited, transsexual prostitutes consulted, Buddhist monks rescued from drunk tanks, all in the service of finding Teddy in time for the upcoming wedding. Individual lines here and there are funny (most of them Galifianakis'), and Ed Helms has perfected his outraged splutter, but this film never achieves the anarchic liftoff the first one did. I didn't love The Hangover—it fell apart a bit in the second half, and none of these performers thrills me to my bones—but even in its weaker moments, that film had more comic integrity than this blatant cash grab. The Hangover Part II's big taboo-breaking set piece (every summer comedy is required to have one now, by order of the Ministry of Tastelessness) comes when the boys meet a "ladyboy" sex worker who claims to have provided services to one of them. The degree of horror displayed by the men when s/he reveals a set of unambiguously male genitalia is more than a little off-putting. Our heroes have, at this point, faced with equanimity the prospect that a teenage boy may be hurt and irretrievably lost in the squalor of the Bangkok underworld. Is the fact that one of them may or may not have had consensual gay sex really the worst possible thing they can imagine?
In case it's not obvious, the R-rated Hangover Part II is not suitable for children (a fact ignored by a couple of morally challenged parents at the promotional screening I attended.) It's raunchy, violent, offensive to every conceivable interest group, and liberally laced with profanity and male nudity. The whole point of this franchise is to make even jaded adults laugh in shock at the outrageous behavior on display. This strategy works best in the final credit sequence, which, in another shameless lift from the original, reveals in a series of rediscovered snapshots what happened on that one wild night in Bangkok. That minute and a half of still photos packs in more dense, economical laughs than all the laborious gross-outs and chase sequences that came before. Maybe The Hangover Part III should consider restricting itself to the slide-show format.