Zodiac tells the story - and every wild goose chase in-between - of the hopeless, hapless search for a blundering killer in 1970s San Francisco. Jake Gyllenhaal plays the obsessive newspaper artist Robert Grayson, an internet geek for a pre-internet age.

Once you're locked into the rhythm of Zodiac's short, dense scenes, throbbing like a steady heartbeat, you're kind of mesmerised. But ultimately it's an experience as maddening, detailed, demanding and repetitive as the obsession it depicts. 160 minutes is a long time to be locked in a labyrinth from which there may be no escape.

Zodiac really is devoted to its story. However, its determination not to stray from the evidence means that the domestic and inter-cop conflicts come across as mechanised. Chloe Sevigny plays the wife to Gyllenhaal's hair-tearing sleuth - but she plays it with flat indifference, so one is never convinced that she truly wants to drag Graysmith away from his books, least of all Mr Fincher.

Ruffalo delivers the film's (and his personal) best performance. As professionalism gives way to disillusionment, and then morphs into frustration and finally ambivalence, his detective inspector is the struggle at the centre of the mystery, while colleagues drop out and cartoonists plunge yet deeper.

The film's aesthetic is largely handsome and static, occasionally interrupted by virtuoso aerial pans and tracks, as if Fincher wants to position the story as lost in a city of stories (a point made rather more concisely in Psycho's opening shot). A late scene in a shadowy basement stands apart from all that preceded it as an incongruous slice of horror melodrama.

After a movie as cold and methodical as Zodiac, perhaps it's no surprise that director David Fincher followed it up with something as saccharine and fuzzy as Benjamin Button.