Okay. Let’s deal with the elephant in the room first of all. There’s a bender in it. Not in the room, in the film I mean. More than one of them. There are benders everywhere in this film, in fact. Now if you are from Blighty and of a certain age and puerile disposition it is impossible to watch this film without sniggering (in a very un-PC and un-reinvented male way) every time benders are mentioned. “I could tell at once you were a bender,” a sage old woman says to a young ‘un as she assures him that he will realise said destiny. A character is dragged off by the nasty soldiers of the proverbial Dark Lord, but that's ok, they explain to the grumbling populace: “It’s a bender.” In my defence I heard women in the audience sniggering too. Some things don’t travel well across the water, and you would think someone might have explained to M Night Shyamalan what the word can mean over here. Granted, the UK isn’t the only place in the world distributing this 150,000,000-plus dollar film, but it is an important part of the European market. The original highly-regarded animated 2005 Nickelodeon TV series from which The Last Airbender derives had a bender in it too of course, and an avatar (the series was known as Avatar: The Legend of Aang as well as Avatar: The Last Airbender) - 'avatar' was dropped from the title of Shyamalan's film, no doubt because he didn't want it to be associated with another, better known piece of mawkish, overblown 3D CGI smoke and mirrors - which is all rather unfortunate, but still, what’s in a name, eh? It is what is inside which counts.

Ah. Yes, what is inside? It must be remembered that this is a film aimed at a young teen market, but that said, the plot has been reduced to fantasy cliché that would make derivative drivel like Eragon (book and film) or indeed Avatar seem like a masterpiece of narrative complexity and imagination in comparison. Aang (Noah Ringer), the young successor in an ancient line of ‘Airbenders’, is reluctant to relinquish his childhood and embrace his destiny as the Avatar, the only person capable of protecting the Water and Earth nations from the Fire Nations, ruled by (Dark) Lord Ozai, who is intent on world domination and who has been hunting down the Airbenders because they're the only folk capable of a slam-dunk when it comes to harnessing all the elements. Meanwhile, Ozai’s son, Prince Zuko (Dev Patel) has been exiled in disgrace from the Fire Nation and nothing but Aang's shaven head will do to restore approval from daddy. The scene is set then upon which nothing less than the fate of the world hangs - and a succession of tired fantasy tropes. At the climax of it all, and after an hour and a half of um-ing and ah-ing, a character decides to harness their true power just when it really matters. Who would have guessed?

You know a film is in trouble when, as an afterthought, it tacks on some 3D effects then promptly gives up on them. One critic at the press screening I attended arrived late and sat through the entire film without her 3D glasses. I was tempted to tap her on the shoulder to point this out but I soon realised that it didn’t matter, because to all intents and purposes the 3D disappeared after the opening credits.

The Last Airbender is the first in a projected series of films, and ends on a molehill-hanger: will-he-won't-he let his true inclinations hang out and openly embrace become a bender (there go those puerile sniggers again)? There is much talk of M. Night Shyamalan’s career trajectory doing the impossible and exceeding terminal velocity in its downward plummet after Lady in the Water (which not even the ever-excellent Paul Giametti could rescue) and The Happening. But this is the same director who made The Sixth Sense and (in my opinion) the even better Unbreakable after that. Shyamalan talked with admirable geekishness at a press conference for The Last Airbender about his love of cinema, comics, action icons, the fantastic and the mysterious, and his passion is clearly undiminished. But he is at his best when he focuses on the internal psychology of people dealing with localised events; the rot set in with Lady in the Water, in which he played himself as a writer with the power to save the world. In Hollywood more (as Avatar proved) is almost always less and no amount of dollars and cutting-edge CGI can disguise hot air once the hyperventilating marketing campaign has blown itself out.

At the same conference, Shyamalan talked about his next venture, from his own independent production company - a series of horror films with storylines by him, but scripted and directed by others. The first, Devil, a supernatural thriller directed by The Brothers Dowdle, is already on the way. This holds out hope of a career resurrection, and so The Last Airbender might yet prove one of the smartest moves in recent Hollywood history: returning to the dead to come back from it. Desperate measures for desperate times. That goes for the audience as well, because the appeal of The Last Airbender extends only to parents and children making a family outing to the multiplex to see Toy Story 3, only to find when they get there that it is sold out.