This film is much like the investigation of the Zodiac murders, steadily losing motivation, ending nowhere and with basically nothing more than loose ends. The acting is not bad at all, neither is the cinematography, but the adventure loses energy as it goes, and seems to lack dramaturgical edges, however much Jake Gyllenhall's character runs around in his obsession to solve the mystery. But Graysmith is at least presented seriously in this deeply grave plot, while other characters, like Robert Downey jr's reporter, who appears like he's some kind of parody act, obviously overacting, as if this is to underline the lack of focus and cooperation within investigators and media. But does that really work? The same also goes for some of the police characters, except from Mark Ruffalo portaying Inspector David Toschi. Together with Chloë Sevigny he probably does the best acting performance, keeping the tension at a certain level. It's sometimes hard to find a good balance and true intention in David Fincher's direction, and it's likely a logic to ending up with a series of questions due to the nature of the plot, which actually lacks a conclusion. But as a drama, it might feel like having been gazing into a dark void that only has been growing more empty. It's perhaps a great point with it, but that's all there is.