Based on the renowned novel by former cartoonist Robert Graysmith, the film follows from the actual events of the Zodiac murders to the possible unmasking of the true killer - although it’s true that the real case was never really solved.

Almost becoming an amalgamation of Son of Sam and JFK, it takes an almost infamous American figure and propels the audience into a world of ‘What if’, and in this case, it carries forth the idea of Graysmith’s novel, what if he discovered who left a trail of bodies in their wake just to find media attention.

You can already see Fincher’s touch the moment the scene opens on sixties L.A and rather than over-glamorising the event or even the murders around the story, he devotes his full attention to the realism behind the story.

Unrelated yet pre-meditated murders taking place in random locations in and around California, with the only connection being a series of letters sent to newspapers in the area, claiming to know details of the murders that only the police or the perpetrator - known only as the Zodiac - can possibly know.

The unknown writer, possibly a schizophrenic or a mentally disturbed person, known only as the Zodiac effectively holds the police, the newspapers and the whole of California in a state of shock as his next targets become wilder and more horrific to behold.

You’ll recognise the dark, subtle tones that we adored in Fight Club and to show that the director recognises the need for human touch in the story, a little humour and irony doesn’t go amiss in the forms of both the over-ambitious Journalist, Paul Avery (Robert Downey Jr) and Mark Ruffalo’s Detective Toschi, as they get further intertwined with the unknown killer’s true identity.

As the film darts from date to date, and location to location, you start to realise how obsessed the main characters become with the Zodiac and how easy it is too assume that obsession leads to involvement as each corner you turn tells you more about the story.

But its Jake Gyllenhall’s distracted Graysmith that somehow finds his way into the plot is one of his best and most understated roles to date, his continuous interest in the Zodiacs puzzles lead to the unearthing of the nature of the crimes and at times, almost leading you to suspect him to be involved.

If you need an engrossing, interesting mystery to unravel through the eyes of others, be fearful of the Zodiac and how it affects those around you.