Since his breakthrough with The Sixth Sense, twist-master general M. Night Shyamalan has become something of a paradox - an original whose movies are getting samey.

If the audience expects a twist, they’ll immediately start looking for one. This makes it harder to conceal, which means swamping the narrative with distracting contrivances. It's a policy of diminishing returns.

Shyamalan is smart but he's all about the set-up. His sleight-of-hand was not quite so deft in Unbreakable; Signs felt like a stage play, and The Village's big conceit was instantly guessable.

Lady In The Water is like Signs in that it leads not to a single never-saw-it-coming revelation but steers a painstaking course through a sea of red herrings and mini-twists.

Originally a bedtime story for Shyamalan's children, it introduces us to Cleveland Heep (Giamatti), the stammering custodian of The Cove, a multicultural apartment block: the United Colors of Barrett Homes.

Who's been mucking about in the pool after hours? grumps Cleveland. Why, that would be Story (Howard) – she’s a 'narf'. And doesn't she have lovely legs? Let's keep the camera on them for a while. And a while longer. And a bit more...

Not knowing what to do with the frightened otherworldly redhead in his shower, Cleveland seeks the help of a trampy Chinese student whose mother is – by lucky hap - an authority on narfology.

Through her we learn that narfs are messengers from the land of make-believe, and Story bears tidings of great import for someone in The Cove.

Her quest involves finding the person whose words will change the world, and requires the involvement of 'healers', 'guardians', 'guilds', 'vessels', 'symbologists' and the like.

Some or all of The Cove's residents may or may not be involved. Their quirks may be relevant to Story's destiny or they may not. They pull together regardless.

There's the Mexican family of seven, the puzzle enthusiast and his son, the animal lover, the recluse, the clique of stoners, the blocked writer and his sister, the bodybuilder who only works one side of his body, and the new guy - a sniffy film critic (as if).

Once Story has delivered her message, a giant eagle will fly her home. But there's an evil beast called a 'scrunt' lurking in the undergrowth, and it will break all the rules of make-believe to stop her from narfing off...

Too silly for grown-ups, too dark and elaborate for youngsters, Lady is a nice-looking mish-mash of ideas loosely held together by Giamatti's engaging performance.

Not a total belly-flop, then, but no cinematic swan-dive either.

Elliott Noble