…Or where David Fincher finally makes a film for grown-ups, and delivers on the considerable promise he has already shown in his previous works Se7en, Fight Club and Panic Room (It’s probably best we forget about Alien 3, isn’t it?) I have had no doubts that he is a director with both a striking visual style, and a handle on how suitably to use digital effects manipulation for dramatic effect. Where I think he has so far fallen down is his rather sadistic attitude towards his stories and characters, that he sets out to shock without there being sufficient justification to. This has yielded the impressively moody but sophomoric Se7en, and the macho-porn parading as political statement Fight Club.

What is different about Zodiac is perhaps explained a little by the real-life story behind the film. A series of murders occur in the Bay Area around San Francisco, and mysterious coded messages are sent to a local newspaper claiming to be from the killer, going by the moniker Zodiac. Naturally, the police set up an investigation team to try to catch the killer, as well as to stop the further killings which are threatened in the correspondent’s letters, but the film also follows Robert Graysmith, a cartoonist based at the San Franciso Chronicle who takes an interest in solving he case. It is unlikely that anyone watching the film will not know that it is based on a factual serial killer, and also the fact that no-one was ever caught for the murders.

Knowing all of this in advance, the audience is thus not kept in suspense waiting for the criminal to be brought to justice, the typical expectation of the serial killer thriller. Perhaps this is why the film has underperformed at the box-office; this is more a subtle character study than a Silence of the Lambs-style manhunt, as of course Se7en was to a large extent. The major theme of the film is actually the obsessive pursuit of the killer by the films protagonists; policeman David Toschi, played by Mark Ruffalo, journalist Paul Avery, Robert Downey Jr in a predictably “Downy Jr-esque” performance, and aforementioned cartoonist Graysmith, played by the ever-watchable Jake Gyllenhaal.

The depths of their obsession with the case takes its toll on their lives, in different ways; disrupting their working lives, relations with their families and friends, and occasionally putting them in physical danger – in one particularly memorable scene involving a basement that you really wouldn’t want to go down into yourself. Gyllenhaal is solid as the geeky Graysmith, though at times a little too expressionless, while Ruffalo is well cast as the wearily inquisitive Avery. Downey Jr, on the other hand, is unfortunately again doing his intensely irritating Robert Downey Jr schtick, which for some may be entertaining, but for me is just plain lazy.

As the years pass by, and leads come and go, the case slowly grinds to a halt, only intermittently propelled along by the persistence of those fascinated by it. But what is their motivation for contiuning to pursue it? Director Fincher and his team spent 18 months conducting their own investigations into the case as preparation for the film, and there is the sense that their own rather macabre fascination with the case reflects that of the protagonsts’. This is the genius of the film, and why it is Fincher’s most mature and thought-provoking work thus far; like in the films of Werner Herzog, Zodiac shows us our fascination with other people’s madness, and how this shows that there is a little of that madness in all of us.