Finding Neverland is a slightly fictionalised account of how JM Barrie came to write Peter Pan. Johnny Depp is Barrie who as the film opens is a struggling playwright with a failing marriage. Things are pretty down for him whatever way you look at it. His plays are critical and commercial disasters, and his wife has no interest in either them or him.

Then into his life comes widowed Kate Winslet and her four boys. He quickly befriends all five, who are still grieving from the loss of their husband and father. Together they all remember that one shouldn't be serious all the time, and through his 'playing' with the boys, Depp is inspired to write his most famous and bestest play.

As befitting a film about the origin of Peter Pan there is plenty of whimsy. Depp scolds the children for using the horrid word 'just'. Nothing is just anything, everything is possible. His vivid games bring some wonder into their dreary lives. Walls disappear and suddenly the children are on a ship surrounded by crashing waves. Their scary grandmother 'inspires' Depp to think up Captain Hook while reprimanding him for wearing an Indian headdress to dinner. Depp, risking society's wrath, whisks the family off to the country to stay at his wife's family's cottage. Neverland is being imagined into life, but disaster is about to strike.

The cast is excellent. Depp and Winslet are about the two perfect actors at the moment. There is pretty much nothing they can't do. Depp just plays a version of his innocent, charming self, with a winning Scottish accent. Winslet is very English, reserved, but with a sparkle in her eye. The kids are great too, all proper manners and fitted jackets, especially the solemn little Peter.

There is also sterling support from silver bearded Dustin Hoffman as Depp's long suffering manager and money man, and from Julie Christie as Winslet's over protective mother. It is hard to tell if Kelly MacDonald, as Peter in Depp's play within the film, is skilfully playing the role of an average actor playing Peter Pan badly, or is just an average actor playing Peter Pan badly. But this doesn't really matter, and overall the performances are excellent.

And, in keeping with all the best fairy tales, Finding Neverland is deeply, deeply sad. Depp's greatest moment of triumph is painfully overshadowed by tragic events back in the real world. It would take a pretty cold and cynical heart not to be moved by the final act.

But that is the point. Barrie's writing, and fairy tales and myths in general, are meant to distract us from the pain of real life, but also to teach us that bad things happen and help us to deal with them. There is a reason you cry both when you are really happy, and really sad. It's probably not just God showing his sense of humour. Hopefully not anyway.