ALFRED HITCHCOCK read a book only once before directing it on screen. This was to ensure that he made something cinematic rather than "filmed literature". This is a wise example that Darren Aronofsky (Black Swan) seems to have taken to heart with his latest film, Noah (Cert. 12A). We get the Nephilim (those heroic giants called The Watchers here), the ark, animals, doves, and rainbow, though not in order of appearance in Genesis 6-9. We are also given a non-biblical love-interest in Ila (Emma Watson), who is sheltered by Noah's wife (Jennifer Connelly). She is unnamed in scripture, but, following rabbinic tradition, is called Naamah in the movie. In effect, of course, this film is in that spirit of Midrash, offering a contemporary interpretation of this section of the Hebrew canon.

In view of recent global deluges, I expected Noah to be more ecological than theological - a cautionary tale about climate change. Not a bit of it. Aronofsky puts this descendant of Seth in contention with the heirs of his murderous brother, Cain, who are deemed responsible for the great wickedness spreading over all the earth. A protagonist needs an antagonist. Every 20 minutes or so, in an obligatory action scene, Noah (Russell Crowe) sees off his arch-enemy Tubal-cain (Ray Winstone, truly the villain of the piece), inside the ark as elsewhere. And, while the spectacular flood scenes were a bit too Cecil B. Demented for me, the film does make them truly believable.

My incredulity confined itself to scepticism at all those Hollywood actors' whitened teeth. Patriarchal orthodontics would not have been so sophisticated. Noah is a godly man, walking alongside the Creator in the way of righteousness. Miracles galore happen: flowers bloom instantaneously out of the ground, forests whoosh up to provide timber, and all living creatures head unbidden to the ark.

But Noah has only partly understood the will of God. Unlike his wife and sons, he believes that God intends them to be the last human beings ever. As a consequence, in a sequence owing more to the story of Abraham and Isaac, Noah intends killing Ila and Shem's twins. Audiences that are unfamiliar with the flood narrative may wonder what sort of God Noah is dealing with, but in this version he comes to acknowledge the defects in his theological understanding, drowning his sorrows with home-made wine.

The primary agent of change is Naamah. If Noah upholds God's sense of justice, it is his wife who reminds us of divine mercy.Together, they comprise the film's metaphysics, its yin and yang.

Our Hebrew ancestors gave new spiritual understandings to the 5000-year-old flood story found in the Epic of Gilgamesh. So, too, does Aronofsky. Numerous other films have been made about Noah's Ark, but usually comic ones, as if the makers didn't dare believe that myths express powerful truths for us.

This latest and fairly solemn Noah would have benefited from some light relief. We wait a long time for that rainbow. Despite the cataclysmic destruction preceding a new beginning, it only tacitly offers hope that God has in Noah found the human race worth cherishing. It is a pity that Aronofsky soft-pedals his source material's covenantal finale. Hitchcock wouldn't have missed that bit out.

On general release from today.