Hmmm. I finally got round to seeing the recent film adaption of I Am Legend starring Will Smith.

I have to admit I was nervous as to what Hollywood had done to one of my favourite books, I’d avoided other, earlier, adaptions for that reason. And quite understandably the film has taken liberties with set up in order to make the film work.

Set in the near future in New York city the film follows Neville, played by Will Smith, as he tries to find a cure to a deadly virus that has killed most of mankind. The survivors have been turned into zombie/vampires with exception of Neville who is immune.

That’s the setup. Pretty close to the book right down to the dead wife and daughter.

The changes early on in the story are all around the switch to film narrative as well as reflecting that the movie is coming out a number of decades after the novel. For example: Neville is a scientist in the film, his dog given to him by his daughter rather than found and of course the cold war has ended.

I was even more optimistic when they spent the first two acts setting the scene for what I hoped would be a faithful conclusion. Then something strange happened, the film went off on some bizarre tangent. It was almost like another film had been grafted on the end.

A real shame.

First off because what appears, at least to this filmgoer, to be a studio driven cop out destroys the impact the book has, it also leaves themes developed and hinted at in the first two acts dangling. For example: a lot of screen time and expensive CGI is devoted to showing that Neville’s interpretation of the creator’s behaviour is wrong and yet there is no follow up.

More importantly it distracts from the shining performance delivered by Will Smith. Everyone raved about him in Ali but for me this is his stand out moment. It’s a tall order to carry the majority of the film as the sole human performer on screen, he manages this not in an extreme over the top way but in a subtle and nuanced performance.

There is the extremely long, tight angle shot of his face in the laboratary scene with Samantha, his dog, an emotionally complicated scene with no dialogue that is genuinely moving. And the street scene where he finally begins to believe he’s going mad – terrifying. These are scenes that do not depend on action sequences, CGI or complex plot twists – just good solid acting.

There are also competent performances from the supporting cast and a woefully underutilised Emma Thompson. The CGI is very well done but the monsters are subsequently not as satisfying as the truly terrifying zombies of last year’s 28 weeks later.

All in all: worth a watch not for the film itself but for Will Smith’s performance and for lovers of the novel you need to be prepared for the film criminally missing the point of the original novel. I would expect an alternate ending on the DVD.