Will Smith stars in this adaptation of Richard Matheson’s classic sci-fi novel from the director of Constantine. The latter is a film I personally enjoyed (and which features a relatively early appearance of the currently prolific Shia LaBeouf) but received some mixed reactions on the whole. By a broadly similar token, I Am Legend has received a fair share of negative reviews, though my opinion is a little more divided.

Things go very well for the first half. It’s nicely paced, concentrating on a depiction of one man’s loneliness taken to the extreme. The script, and Smith’s acting, handle the material well. The deserted and destroyed New York looks as stunning as the trailers promised, while the CGI animals that roam it are as good as any. The flashbacks that punctuate the film are well executed too, drip-feeding clues to what happened while maintaining some mysteries of their own. There are some other good sequences: Neville’s exploration of a pitch-black Dark Seeker-infested building is tense, and the death of his pet dog — his one remaining companion — is moving, even if it was given away in the trailer. That scene is effectively played and shot, showing only Neville’s face as he is forced to euthanize the diseased animal by suffocation.

Sadly, this is where things begin to go down hill. The Dark Seekers — the film’s vampires/zombies/whatever — are crafted with pretty good CGI, but they’re still not life-like enough to work. If it were a mindless blockbuster they would’ve been more at home, but as it’s managed to be an effective drama they feel entirely out of place. It’s true that real actors couldn’t have managed the physical feats the creatures are made to pull off, but do they really need to do those things? I suspect not. The film also leaves several holes in the Dark Seeker’s actions — for example, they copy Neville’s trap, a move apparently beyond their intelligence, but the film neglects to explore why or how they did this.

Instead it moves on to the arrival of some more survivors. Quite where they came from, or how they got into the supposedly isolated Manhattan, is another inadequately explained set of circumstances. After they arrive, the film’s climax comes out of nowhere. It’s as if the screenwriters ran out of ways to keep things going so just bunged on a big climactic action sequence. And what happens in it is pretty silly too, especially Neville’s self sacrifice — why not get in the Magic Safe Hole too and then chuck the grenade out? Perhaps he just has a death wish by that point. It would seem most of the audience did. There’s also a pathetic epilogue, and an even worse final line that attempts to make sense of the title.

I Am Legend is something of a disappointment. The considered and effective first half gives way to an increasingly nonsensical second, marred by numerous flaws that stack up til a near-laughable conclusion comes from nowhere. I’ve been told that the ‘alternate theatrical cut’, with a handful of additional scenes and a new ending, is marginally more effective. I’m sure I’ll watch it someday and share my thoughts. For now, I Am Legend’s two halves of differing quality just leave it in the middle of the road.

I Am Legend is on Watch tonight, Saturday 11th October 2014, at 9pm. It’s on again on Tuesday, when I’ll (re-)share my thoughts on the so-called “Alternate Theatrical Version”.