That was a waste of time. My reason for disliking this film isn't that it's got almost nothing to do with Death Note, but simply because it's a poor film.

Quick catch-up on why this film exists and why we're being expected to watch it. Death Note went global in 2006, including two live-action Japanese films that did chart-topping box office and were extremely popular. Naturally the producers' thoughts turned to a sequel, so here it is. Technically it's a sequel that takes place within the second Death Note film, but that's a technicality. It's a sequel, or if you prefer a spin-off. The important thing to know is that there are detailed spoilers for everything that happens at the finale of their version of the Death Note story, so don't even contemplate watching this if you haven't seen the first two films. Light, Misa, Ryuk and Yagami show up, but only for cameos. The only real returning character is L. He's the world's cleverest detective, after all, and he's got another case to crack.

At first I thought this sounded great. My main objection to the first two Death Note films had been their undercooked Light and L, so giving over an entire film to L sounded like a good idea. Unfortunately he's even more poorly served here than he had been in the last two. He gets quite a lot of screen time, but precious few opportunities to flex his intellect and no real clash of wits with the enemy at all. He gets one cool bit, but this merely involves him showing up in a corridor and throwing something. Is he clever? Not particularly. Instead the director Hideo Nakata said he wanted to show L's "human side" which hadn't been explored in the Death Note series, so L finds himself looking after a small boy and a thirteen-year-old girl.

Then you've got the lacklustre and occasionally stupid story. A bunch of principled eco-terrorists want to wipe out most of the human race in order to save the planet. Their plan for doing this involves using a bio-weapon, but obviously they're not planning on setting it off without having injected themselves with the antidote first. Thus the plot turns into nothing more than a McGuffin chase, except that the McGuffin is that aforementioned thirteen-year-old girl (a professor's daughter) and there's actually not much L can do except stay on the run from bad guys and tell scientists to work faster. At one point L's scientist says he's produced an antidote but not tested it yet, at which L cheerfully thanks him and runs off with it. Three cheers for the scientific method. However more damaging than here stupidity is the fact that the film was starting to bore me, with a point in the second half of the film where I couldn't see the point of what was happening. Our heroes were on the move, but not apparently going anywhere.

Then comes the finale, in which the eco-terrorists are planning to fly to America and release their virus. To do this, apparently they're planning to hijack it in mid-air. Well, that sounds sensible to me. After all, America's famous for its relaxed attitude towards suicidal mass-murdering terrorists who've hijacked planes, so I'm sure they'd have been allowed to land safely. The alternative of meekly getting off the plane with the rest of the passengers and disappearing into the crowds presumably never occurred to them. That's also assuming they'd have been able to fly there across the Pacific Ocean in the first place, since I believe it's hard to pilot a plane when you're dead.

In other words, the plot's negligible. At times it's as if they were trying to make a dumb action movie, but didn't have enough money for much action.

That's unfair, of course. There are two reasons why. The first is that there are a few sequences here that seem to have had a bit of money spent on them. The location shooting in the Thai village looks great, especially when it turns into a helicopter chase with missiles. If only the Sakura TV siege in The Last Name had looked this good. The other reason why it's an unfair criticism is that this is a rather earnest film, going out of its way to present the eco-terrorists' point of view and to give big scenery-chewing scenes to some under-acted characters. I've heard it rumoured that this film's acting got praised in Japan, although personally I find that hard to believe since I found the performances underwhelming. They're not horrible (except for the children), but I thought most of the actors were operating at 90% at best. The script's giving them opportunities. There are serious issues being debated here and some scenes that could have been genuinely powerful, but the opportunities aren't being taken.

Not everyone's bad, of course. It's slightly disconcerting to watch Youki Kudoh trying to give a proper performance in the middle of all this, while of course Shunji Fujimura is still adorable in his cameo as Watari. This film should have been Watari: Change the World. I'm serious. There's nothing L does here that Watari wouldn't also have been capable of, especially when you bear in mind that the original manga's Watari could if required shoot people. Ken'ichi Matsuyama isn't bad as L, but again I never felt he'd found a dimension beyond the mannerisms. He's also handicapped by the script requiring him to talk not just in Japanese but also in Italian, French and quite a lot of English, which the actor clearly can't speak and is merely delivering phonetically. Sometimes he's not easy to understand.

It's unsurprising that Youki Kudoh's giving the best non-Watari performance here, since she's a movie actress with both a Japanese and a Hollywood career. She's been in Mystery Train (1989), Heaven's Burning (1997), Memoirs of a Geisha (2005) and, um, Rush Hour 3 (2007), but I think we can forgive her the last one.

There's a surprising amount of gore. The eco-terrorists won't just kill you with an ordinary handgun, but with either a shotgun or for preference a knife. That's not too bad, but the virus at times can be gross. Don't watch this film if you can't handle a bit of people bleeding from their eyeballs and so on.

Fundamentally, this isn't a particularly interesting film. It's earnest without being intelligent and has big dramatic scenes of ethical dilemmas that aren't being acted as powerfully as they needed to be. Youki Kudoh's pretty good, though. Furthermore L is largely generic and there's very little here to attract the Death Note audience that they're presumably going for, although I did note at the end that the Thai boy receives the name of Near and gets given Near's robot from the manga. The music is ludicrously overblown at the end. Oh, and I haven't even mentioned the credibility drop for an English-speaking audience that accompanies badly done English-language dialogue in a Japanese film.

"It is extremely dangerous and fatal."