The inevitable comparison for Filth, even if just from a marketing perspective, is Trainspotting. But despite the similarities - drug addiction, the downbeat Scottish milieu and the same author of their source material - they strike very different tones. While Danny Boyle’s films have very distinct subjects and genres, pervading over many of them is a queasy optimism. His characters do endure great hardships but their happy endings sometimes appear out of nowhere, and out of proportion with their previous struggles - the musical number in Slumdog Millionaire or the rescue helicopter in 28 Days Later (a more ambiguous, unhappy ending was removed after it tested badly). With Trainspotting, Renton, a character who is introduced shoplifting to pay for his heroin addiction, walks into the sunset free of his former friends, although perhaps not of his addiction, with sixteen thousand pounds. From the beginning it’s clear the same is not going to happen in FIlth.
FIlth is, like its protagonist Detective Bruce Robertson (even anti-hero is too generous), misanthropic to its core. The tone lurches with him from black comedy to straight drama, daring the audience to hate Bruce as he uses any means necessary to gain a promotion. But really the world around him is just as violent, racist, misogynistic, and homophobic as he is, or plays at being. As the only one who realizes and exploits this, he earns a weird measure of our respect.
As with many niche market films, Filth opens with a parade of logos - it took money coming from a lot of different places, spreading as much of the risk as possible, to get this made. Rather than a frustration, these should be viewed as badges of honour, especially as, apart from the constantly blown out TV soap windows, it never looks cheap. Even with, or perhaps especially with, James McAvoy’s star power, this is not an easy sell to your mother - it’s no Atonement. The film even throws the wish fulfilment appeal of watching bad characters behave badly, a la The Wolf of Wall Street, back in your face - giving the finger to a child with a balloon is one thing, sexually abusing a minor is another.
Several mysterious backstories are woven together, any one a potential twist. However any time a simple psychological explanation comes within grasp it twists out of reach. Wisely the film avoids diagnosing Bruce beyond “extremely troubled” and “on medication” - you can speculate based on his medication (lithium apparently, which has been used to treat bipolar disorder) but there’s no chance of pinning it down. He’s more a force of nature, an agent of chaos, than a specific disorder.
Similarly the camerawork is restless, always being pushed back by McAvoy’s long strides. He is literally in your face. The reality-disrupting moments - a fantasy version of his wife Carole and a nightmare version of his psychiatrist (a wonderfully camp turn from Jim Broadbent) are actually fairly easy to take, as both are firmly rooted in his imagination. There’s some visual trickery with Carole delivering her lines to camera via several mirrors, but it still plays according to convention, which lulls the audience into a false sense of security. (The payoff for these scenes is undeniably brilliant.) It’s the same with the flashes of pig masks and other weird images - they’re startling but well within what might be expected from a horror film. What is genuinely unsettling and disturbing are the three or so times James McAvoy looks directly into camera, particularly the last. They suggest he’s well aware of his existence as a character and what you might think of him. He’s playing by everyone else’s rules and the same rules apply.