Grim and bear it in 'Hangover Part II'

'I can't believe this is happening again!" is the oft-repeated line in "The Hangover Part II," although it's definitely not happening again. Two years ago, our party boys got lost in a deliriously funny walking coma, during which what happened in Vegas not only didn't stay in Vegas, it generated $270-odd million at the box office. This time around, the same crew is despoiling Bangkok, but the general tone is less Judd Apatow than David Lynch, the story less comedic than cautionary.

Which may not be what "Hangover" fans are looking for. "Hangover II," directed again by Todd Philips, is a classic sequel: It rides the goodwill of its ancestor, while betraying, or overdoing, the same qualities that compelled it to be made. Few audiences approached "H1" thinking it was going to be much more than frat-boy stuff, but there was an unexpected bite in the idea that our mild-mannered heroes would do just about anything, given the proper pharmaceutical/erotic stimuli.

This film has to go further, deeper and darker, and audiences may end up craving a few bonbons of pure unadulterated hilarity, hold the Freudian/ Southeast Asian condiments.

But from the opening shot, "Hangover Part II" is pretty grim. This time, Stu (Ed Helms) is the one getting married, to Lauren (Jamie Chung), whose father (Nirut Sirichanya) despises him. Dad dotes on his pre-med, cello-virtuoso son, Teddy (Mason Lee), so the first thing the boys discover after waking up in Bangkok is that they've lost Teddy. Except for his finger.

How they get to that point sets up the principals -- Phil (Bradley Cooper), Stu, Doug (the virtually MIA Justin Bartha) and boy-man Alan (Zach Galifianakis) -- but fails to deliver on the comedic promise. The inherent joke of Alan -- the "stay-at-home" son -- isn't properly exploited by the script; none of the others, notably Cooper, is an organically funny actor. The one bright spot is Ken Jeong, who, as the flamboyantly criminal Mr. Chow, generates the few belly laughs "Hangover Part II" manages to squeeze out of an overproduced, undernourished story.