In a mainstream movie comedy there is usually sixty minutes of zany shenanigans – which I actually thought was an Irish bar until told otherwise – followed by twenty minutes of stone cold serious stuff followed by a ten minute comic sprint finish. THE HANGOVER PART III is that twenty minute part of a comedy stretched to a hundred minutes. There are some laughs, but they tend to be rather small. It only really rekindles that HANGOVER feeling in the end credits: the morning after an incredible night and Stu (Ed Helms) has eaten some really dodgy wedding cake...

Whizz back to the beginning and we’re in slow motion action movie mode. A warden of a Bangkok prison races across the screen. There is a riot and Mr Chow (Ken Jeong) – Leslie to his friends (does he have any?) has escaped. Cut to Alan (Zach Galifianakis) who is driving down the freeway towing a giraffe. Why a giraffe? Because Alan does not think things through! Needless to say, said long-necked beast causes a multi-car pile-up. Does Alan notice? No, he’s a 42-year old man child, the kind who marches into a room and says: ‘Mother, Oreo milkshake, now!’

Alan is not a particularly likable comedy character. Neither, for that matter, is Mr Chow. I have a rule: a comedy can only sustain one such figure, the annoying misfit; two of them and you’re heading for the exit.

So Alan’s father (Jeffrey Tambor) has died. The beautiful sound of ‘Ava Maria’ can be heard at his funeral. Who is singing it? If you’ve seen the trailer you know the answer. The ads basically give you the best jokes. What you have left is a thriller plot.

Alan’s friends, Phil (Bradley Cooper) and Stu and his brother-in-law, Doug (Justin Bartha) make an intervention. Alan needs to be weaned out of his man-childhood. They drive him to ‘New Horizons’ – ‘it does sound good,’ agrees Alan – but then they get the car bumped and the four men are snatched by raiders in piggy masks.

Now I know what you’re thinking? Where’s the booze? Well, there is none and I am not just talking about the dearth of beer at the London West End press screening I attended – okay, I’ll be on time at the next one.  Alan, Phil and Stu have to do some hero stuff. They have to find Mr Chow for a ruthless gangster (John Goodman); the Wolfpack must become bloodhounds. Doug is kept as collateral. ‘Take Stu!’ wails Alan.

Still laughing? I thought not. Would you believe it but Mr Chow texts Alan and says he wants to meet. He’s in Tijuana. Time for some impromptu intoxication and crazy goings on? Er, no.

After a botched attempt to capture Mr Chow – they want to lure him into a cinema and drug him – the four men decide to recover Mr Chow’s gold from his old house. Wires have to be cut simultaneously. Only Mr Chow is colour-blind.

Expecting a double-cross? Of course. We have a thriller plot. But then the Wolfpack get a second chance as charges are dropped.

Still time to throw in some unexpected twists? Not quite. Alan recovers his mini-van by using Alan’s find-a-phone app. Cue a whinging speech from Alan about losing your phone. You’d lose it and you’d have to reload 60 apps. How disastrous. Alan meets the love of his life, Cassie (Melissa McCarthy, the obligatory not-so-surprise cameo) who works in a pawn shop. They share a lollypop. The woman crushes it.  Wouldn’t you know it but Mr Chow has cashed in an ingot and intends to blow it on women and drugs. Alan knocks over stuff.

But where is Mr Chow? How can the trio find one crazy Asian in a city of – well, one imagines there might be many more. Stu calls in on his ex-surprise bride (Heather Graham) who now has two kids. She makes some calls.

There then follows one of the creepiest scenes in modern cinema as Alan bonds with the ex-stripper’s four year old son. They talk in the kid’s tent and Alan says he is the child’s father.

There is a race to Caesar’s Palace. Mr Chow has hired protection. He is in a penthouse suite with coke and women. Phil and Alan scale down from the roof to apprehend him.

At this point, there is real danger and the film is almost funny. Do they capture Mr Chow? That would be telling, but the trailer illustrates the chase sequence and Mr Chow’s big line: ‘I love cocaine’.

It all ends in the desert. Shots are fired. Matters are resolved. Alan decides to stay behind. Well, we saw that coming. A kiss and then trousers are dropped. Men children, eh?

Cut to six months later. Cassie and Alan get married. Cue a sentimental montage, then the credits.

Then comes the hangover.

I have described the film so you don’t have to see it. Save your dollars or rupees (I have at least one Indian reader, thank you sir). Just tell your friends, the final scene that’s funny – the monkey strikes back. The rest of it is pretty lame.

Did I tell you the characters get attacked by Mr Chow’s chickens? Well there has got to be animal action at some point and also a blackly comic moment when Mr Chow smothers one. If that does not sound funny, don’t say I didn’t warn you. The perpetrators are director Todd Phillips and his co-writer Craig Mazin. The trailer for WE’RE THE MILLERS, featuring Jennifer Aniston as an erotic dancer posing as a housewife has some promise. Drug smuggling is involved, which as we know isn’t that humorous.