I'd like to kick this review off with a question: can anyone name a film trilogy in which the third installment was not the weakest? The Matrix Revolutions. The Dark Knight Rises. The Godfather Part 3. Even Return of the Jedi has garnered the most criticism of the original Star Wars trilogy (the Ewoks can probably be considered the start of George Lucas' descent into Jar Jar Binks territory). There are even fewer comedy trilogies to speak of, but of those that do come to mind - Back to the Future, Austin Powers, The Naked Gun - the pattern seems to just about hold.
Maybe it's because endings a hard. The first film introduces us to a world and a set of characters, the second film introduces greater conflict and deepens our understanding, and it's up to the third film to provide some sort of closure and draw it all together in a satisfying way. The better the preceding films, the more difficult the task. It may also have something to do with the studios: if the franchise's engine is still running by the time the third installment comes around, it's easy enough to pump more money into it, see how far it'll run, even if it's been idling for over a decade (see: Indiana Jones and the Kingdom of the Crystal Skull, Live Free or Die Hard.)
Somehow you have to find a way to keep it fresh while sticking to the formula. It should, in theory, be easy: Indy goes after the treasure, John McClane takes on the "terrorists". But, In the case of The Hangover series, the premise is fairly simple: an eclectic group of friends comprised of the laid-back Phil (Bradley Cooper), nebbish dentist Stu (Ed Helms), unremarkable Doug (Justin Bartha), and beardy man-child Alan (Zach Galfianakis) go on a stag do and somehow succeed in a) waking up in a bizarre situation, i.e. with a tiger or monkey in their hotel suite, and with no memory of the night before and b) with Doug nowhere to be found. The rest of the film inevitably follows their attempts to uncover what happened the night before and locate their missing friend.
If plausibility is a key part of your cinema-going experience - after all, as John McClane said, "How can the same thing happen to the same guy twice?" -then The Hangover Part III may not be "your type of film". While the third installment changes up somewhat on the premise of the first two films, it loses nothing of the sense of weirdness; if anything, it's got bigger and darker. The film's opening sequence involves a Shawshank-inspired jailbreak from a Bangkok prison during a riot with the 'Hang in there' cat standing in for Rita Hayworth. Director Todd Phillips has described the trilogy as a "three-part opera of mayhem and bad decisions" and, for my money, that sounds spot-on.
The film opens an unspecified period of time after the events of The Hangover Part II, but long enough that Phil, Stu and Doug have all settled into their roles as married men. Alan, however, is not doing so well. He's off his medication and, as an incident involving a giraffe and a low bridge has throws into harsh relief, has lost whatever self control he once had. Galfianakis had made a career over the past few years of playing oblivious but ultimately loveable dolts, but by now Alan has become gratingly abrasive. He treats those around him so badly - knocking over a drink and forcing his housemaid to clean it up during her well-intentioned speech at his intervention, casually mentioning during his father's eulogy that he wishes his mother had died instead - and displays so little self-awareness, it feels uncomfortable to laugh at a guy who is so clearly mentally ill.
Anyway, the Wolfpack, as they are known, band, albeit reluctantly, together to take Alan to rehab in Arizona. En route, they are run off the road and captured by a crime boss, Marshall (a largely wasted John Goodman), who wants the gold their former partner-in-crime Leslie Chow (Ken Jeong) stole from him. Given that Alan is the only one to have been in touch with Chow since he was imprisoned in Thailand, Marshall gives them three days to track down the psychotic Chinaman and recover his property. He also takes Doug hostage as collateral. Poor Doug. As such, Phil, Stu and Alan set off on a journey that will take them to Tijuana, Las Vegas, and finally back out into the desert.
The Hangover series has always been peculiarly character driven, drawing its comedy not only from absurd set pieces but it's protagonists horrified and hysterical reaction to them. To this extent, the property feels played out. Phil and Stu are now well balanced, contented individuals - their arcs over -; as such, this final installment is all about Alan's long-overdue maturation. On the set piece front, we have, to name one memorable instance, a limousine-driving Stu racing along the Sunset Strip to intercept a parachuting Chow (who spends his flight singing 'I Believe I Can Fly' and gleefully exclaiming "I love cocaine!"). On the character development front, we get pawnshop owner Cassie (a basically cameo-ing Melissa McCarthy) whose vulnerable obnoxiousness is a perfect match to Alan's, even if their displays of affection are pretty grotesque.
The movie also goes out of it's way to showcase Jeong's Chow, who started off as a bit part in The Hangover, graduated to become a major supporting character in Part II, and now, by Part III, has basically become The Devil. He, more than Marshall, feels like the series' antagonist. If you've ever seen the TV show Community, Chow is basically a supercharged version of Jeong's character from that show. With his no-holds-barred debauchery and the sadistic pleasure he takes in screwing with everyone's lives, Chow is a great comedic character, but he overwhelms everything else. It's difficult to focus on the jeopardy of the situation when Chow takes a time-out to perform a terrifying rendition of Johnny Cash/NIN's 'Hurt' or smother a fighting cock with a pillow.
Despite it's cruder aspects, much like Alan, The Hangover Part III has a lot of heart to it. Alan's reunion with the baby from the first film is actually sorta touching as he tries to take up what he sees, however wrongheadedly, as his parental responsibilities. In fact, not to get too portentous, Alan could be seen as an embodiment of the instant gratification, ADHD culture in which we live. A scene in which Alan grandly invites Cassie on a date also sees him drop trow with the scientific pronouncement "I saw it in a porno-graphy". If Alan is a hierophant of the age, in a series that has become increasingly apocalyptic, it's comforting that we leave him here.
In that The Hangover is not a series that necessarily has a natural progression but is more akin to iterations on a them, I'm glad Phillips and Co. have chosen to leave it here before the entertainment value plummets. The Wolfpack have come about as far as they can come as characters and the gags have got about as outlandish as they can get. Unlike, for instance, Ghostbusters (which, against my better judgment, I long for a threequel to), there's not endless potential for further adventures - the formula has been stretch far enough -, but if you liked the previous two, chances are you'll like this.
Verdict: The Hangover Part III is an off-kilter merry-go-round of a movie and a generally funny if overly twisted addition to the franchise. It's got a great soundtrack and a mid-credit sequence that features some unexpected (probably unwanted) nudity, taking the characters full circle, and leaving us in an appropriately "WTF?!" place. It's not, say, Toy Story 3, but it's no Spiderman 3. If you like your humor like a bad trip, you should probably give it a look.