From the outset, through the film‘s brilliantly designed deliberate under-lighting - we see very little blood and guts - and muffled sound, the audience is encouraged to lean towards the screen, immerse itself in the film‘s unbearably grim world.
Pitt is in career-making form as Mills, a simple cop moving with his sweet young wife (Paltrow) to a grim, anonymous city, determined to make a difference, to do some good. He is assigned to track down a vengeful killer, and works alongside Somerset (Freeman), a jaded, wise policeman on the verge of retirement.
The two are that modern movie cliché - the mismatched pair thrown together by circumstance, who gradually learn mutual respect. But Fincher and Walker take these hackneyed ingredients, play with them in the context of a brilliantly cohesive plot, and present something consistently fresh - the police finding themselves with too much evidence, the premature unmasking of the killer - and very, very dark.
