The brutal disaster that is “The Hangover Part III” is the summer movie equivalent of that curious beverage mixed among the two-liter bottles of soft drinks at your neighborhood drug store called “wine product.” It looks like wine. It’s in a wine bottle. But make no mistake – it’s not wine.

It’s a strange, off-putting concoction, an assembly-line attempt at luring unsuspecting shoppers who see the word “wine,” the low, low price, and figure, why not? Here’s why not: Because wine product and “The Hangover Part III” are tasteless, poor-intentioned and completely unnecessary.

It is easy to forget, watching the third, and supposedly final, film in the series that the original, while overrated, had its moments. (It was certainly above wine product on the beverage scale – let’s call it box wine.)

Todd Phillips, the director of the great “Old School,” put together a good trio: Bradley Cooper, the likable cad; Ed Helms, the stressed dentist and Zach Galifianakis, the obnoxious man-child. There was even an ever-so-slight social commentary in the concept of Las Vegas as drug-fueled bourgeois playground of the embarrassingly middle-aged.

“The Hangover Part II” was occasionally funny but startlingly derivative, transplanting the action to Thailand and heading in increasingly grim directions.

The second movie was a hit, but “The Hangover Part III” should prove a box-office disappointment after a big opening. There are virtually no laughs this time around, and Phillips and company never demonstrate why the film even has a right to exist.

As the film opens, Galifianakis’ Alan is out of control, having killed a giraffe (it was in the trailer, so don’t call that a spoiler), and inadvertently caused the death of someone else in his life. His brother-in-law Doug (Justin Bartha) enlists the other reluctant members of the self-proclaimed “wolfpack,” Cooper’s Phil and Helms’ Stu, for an intervention.

The intervention scene is one of the film’s few high points, with Galifianakis at his sneering, entitled best. Phil, Stu and Doug offer to get Alan some real help, but then come the gangsters, led by a game John Goodman, the kidnapping of Doug, and the inane development of the film’s central plot.

It all involves the most ludicrously unfunny character of the series, “Community” star Ken Jeong’s Mr. Chow, and this, above all else, is the film’s most crucial miscalculation. Hinging the plot on such an annoying, unmemorable figure was a keeping-Darcy Regier-like mistake, and the film never recovers.

For the remainder of the thankfully short movie, Phil, Alan and Stu must chase Mr. Chow, first to Mexico, and then, of course, to Vegas. There are a few random chuckles, but no real belly-laughs, and if a “Hangover” film lacks at least one OMG moment, why bother?

The de rigueur end credits sequence aims for that dubious achievement, but predictably fails. It’s a “wild” minute or two that ranks among the ugliest, most mean-spirited moments in recent American comedy. As usual, it involve Helms’ Stu.

In supporting roles, Melissa McCarthy steals her scenes as a pawn shop owner who makes a love connection with Alan, and Heather Graham returns for a reminder that she is a likable screen presence. Even the first film’s baby returns – it’s the same actor, in fact – as a cute toddler.

Still, no one involved comes off well. (OK, maybe the toddler.) For Phillips, whose last non-“Hangover” project, “Due Date,” also missed widely, this is another setback. For the film’s central trio, especially Cooper, it’s merely a brief misstep.

In the years since “The Hangover,” Cooper has become a real, bankable star, and a very good actor. His Oscar-nominated work in “Silver Linings Playbook” and less heralded but no less effective performance in the stunning “The Place Beyond the Pines” confirm that he does not need this kind of gutless romp anymore.

For the sake of all concerned, then, I hope the series is buried in the desert – perhaps the spot where Joe Pesci’s Nicky met his grisly end in “Casino.” That’s how you end a Vegas film.

the hangover part III

One star

Starring: Bradley Cooper, Zach Galifianakis, Ed Helms, Ken Jeong

Director: Todd Phillips

Running Time: 100 minutes

Rating: R for pervasive language including sexual references, some violence and drug content, and brief graphic nudity

The Lowdown: To find their kidnapped friend, the “wolfpack” must track down their old nemesis, Mr. Chow, and return to Las Vegas.