After months of waiting, the first official trailer for Todd Phillips' 'The Hangover: Part III' is finally here - and guess what? The boys are heading back to Las Vegas. The promo promises that "it all ends here," which is probably just as well given the dismal critical reception of the sequel.

Phil, Stu and Alan - aka Bradley Cooper, Ed Helms and Zach Galifianakis - are all back for one last drunken adventure. The trailer begins with the sounds of Franz Schubert's 'Ave Maria' - though it's not some Italian tenor singing the words, it's Alan pouring his heart out at a funeral! "My god - he has the voice of an angel," Phil observes, "It's breath-taking!" says Stu.

And then we're back in Las Vegas.

It's unclear why the guys have decided to return to Sin City, and Stu somewhat painfully states, "I swore to myself that I would never come back," and that "someone needs to burn this place to the ground." On the evidence of the trailer, the Wolf Pack do a pretty good job of doing just that. We see a man getting murdered in front of their very eyes, a body dropping into a pool, and Alan slowly placing a lollipop in the mouth of Bridesmaids star Melissa McCarthy. We also get a glimpse of Mr Chow in a police officer's uniform and - hurray! - the return of Heather Graham. 

It's looks as though we're all in for a pretty wild conclusion.