I highly recommend this movie if you're a fan of Shyamalan. Out of his movies I would say this is one of his best, standing alongside The Sixth Sense, Signs and The Village in particular.
Story (Bryce Dallas Howard) is a water nymph (known as a Narf in the movie) who is found to have emerged from a pool belonging to a middle aged man who owned an apartment complex. The owner Cleveland (Paul Giamatti) toppled into the pool after falling unconscious when he slipped on the edge, knocking his head on the concrete. Story rose from her home (known as the Blue World) to prevent Cleveland from drowning and returned him back to hit shelter.
When Cleveland awakes he asks the girl countless questions about who she was and where she had appeared from. Story refused to tell him and claimed everything he wanted to know was a secret so explaining herself to him would only cause her harm. Seeing the situation as bizarre and not believing everything Story said, he took it upon himself to carry her out into the pool so she could wake up and remember who she was. This was probably his biggest mistake.
After almost colliding with a very fierce lupine like creature (known as a Scrunt), he started to believe everything Story was telling him. It got the point whereby he knew he had to protect her so she could somehow return to her home in the Blue World without being attacked by the horrid creature. Making decisions to weigh up his options, he asked around the complex to find certain people that Story had mentioned would help her along her journey. He found them.
The residents of the building managed to fight off the nasty creature using the powers she had told them controlled the vessel which would enable her to return home safely without being torn apart by the nasty threatening Scrunt.
There wasn't really a dull moment throughout the whole movie so it was really entertaining. It also had me wondering whether stories like that.. could be true.