From a Las Vegas bachelor party to a wedding in Thailand to... the gambling capital of the Nevada desert.

Three films and exactly four years later after Todd Phillips’ original blockbuster hit, we’re back where we started.

In Vegas and wondering what’s going on.

The difference this time is that the filmmakers’ themselves don’t seem to know, either.

While Phil (Bradley Cooper), Stu (Ed Helms) and Doug (Justin Bartha) have moved their lives on, Alan (Zach Galifianakis) is turning this into another adult variation of the old hit, Three Men and a Baby. 

And he’s junior, having ditched his medication.Meanwhile, with Leslie Chow (Ken Jeong) out of prison ready to cause mayhem and bad boy Marshall (John Goodman) not happy with any of our anti-heroes, all hell is set to be break loose in a story about revenge and missing gold.

Like its immediate predecessor, there are significant problems with the opening of this film.

The giraffe sequence is as pointless as it is badly filmed. 

The original film’s tiger was worth the effort, but the dodgy effects here remind you that if you can’t do something properly, don’t bother.

With the gang caught between Marshall and Chow, the action moves on to Vegas itself and, thankfully, rarely has it looked better on the silver screen.

Much of action is shot with big, fat lenses, adding a lustre and a gloss to the city of the night which makes up for the paucity of the script.

But there’s little tension, few genuine laughs and not much of a connection between various scenes.

Guest star Melissa McCarthy ends up virtually playing the same character we saw earlier this year in Identity Thief, only Cassie is less vindictive than Diana was.

After several false endings, the inevitable end-credit extra scene tries to pay homage to the 2009-source material of The Hangover.

Sadly, it’s too little. And far too late.