“It’s happened again,” Phil (Bradley Cooper) says at the beginning of the new film, “The Hangover: Part II.” For fans of the original, what has happened is pretty obvious. The “Wolfpack,” composed of Phil, Stu (Ed Helms) and Alan (Zach Galifianakis), have spent another wild night partying and can’t remember anything about it. Like in the original, the men have lost one of their friends and must spend a day trying to find him before a big wedding.

The sequel begins a few years after the original. Stu is now engaged and his fiancée’s family is waiting for him to arrive at the wedding in Thailand. Phil calls to inform them that another late night has turned disastrous for the “Wolfpack.”

The story then flashes back to the events leading up to the wedding. Alan, who drugged his friends in the original, is waiting for his invitation to Stu’s wedding but Stu, for obvious reasons, doesn’t want to invite him. After Doug (Justin Bartha), whose wedding took place at the end of “The Hangover,” pressures Stu to invite his brother-in-law, Stu relents. Joining the “Wolfpack” and Doug on the trip to Thailand is Teddy (Mason Lee), the teenage brother of Stu’s fiancee.

When the group arrives in Thailand, they decide to have “one drink” on the beach at night a few days before the wedding. The next morning, the “Wolfpack” wake up in Bangkok hung over. Doug left the beach early so he’s back in his hotel room but Teddy is missing. As the story continues, the “Wolfpack” spend their day investigating what happened the previous night and trying to find Teddy.

This story follows the same formula as the original film. However, the concept now feels tired. Part of the fun of the original was not knowing where the story was headed or where their search would lead. From the beginning of “The Hangover: Part 2,” it seems obvious how the story will end.

One of the biggest differences between the two films is the sequel’s focus on raunchiness and vulgarity compared to the original. The filmmakers try to top the original but instead of focusing on more clever and original comedy, they simply included more unfunny raunchiness in it along with a lot more male nudity. Once the “Wolfpack” wakes up, the crude humor takes center stage and never lets up.

In fact, the best part of this story is before the men wake up hung over. The scenes of the gang getting back together and a look inside Alan’s warped daily life (complete with a “Genius at Work” sign on his bedroom door and pictures from the original drunken night gracing his walls) are the funniest bits of this story. It’s later on that the story relies on sex jokes and nudity to keep it going.

That’s not to say that “The Hangover: Part II” doesn’t have its moments. The best parts of the film are in the beginning but Alan does have a few funny one-liners scattered throughout the story. However, this movie ultimately becomes sleazy and nearly unwatchable.

Part of the fun of the excitement of the original “Hangover” was the originality of some parts of the story, its quirky humor and an interesting mystery that held the story together. “The Hangover: Part II” lacks all of these qualities. It’s a crude sequel that follows the formula of the original but lacks the charm of its predecessor.