Filth (2013; Directed by Jon S. Baird)

Detective Sergeant Bruce Robertson (James McAvoy) is a bad cop. Not just in the “bad egg” corruption sense, nor merely in the sense of not being terribly effective, though both descriptions most certainly apply. In the quest for a promotion in the Edinburgh Police Department that he feels will mend up his marriage to his wife Carole (Shauna Macdonald), which is on the rocks is an unspecified way, DS Robertson will do just about anything to set his rivals for the Detective Inspector spot against each other and to make himself the most obvious choice. At the same time, he’s also a hedonistic whirlwind of overindulgence, popping pills, swallowing whiskey by the bottle, frequenting prostitutes, pornography, and kinky sex with the wife of a colleague, and engaging in a shady blackmail con of a Mason lodge brother and mild-mannered accountant (Eddie Marsan). And he’ll do just about anything, inside but especially outside of the law, to solve the murder of a Japanese student and earn his promotion.

Filth is based on Irvine Welsh’s book of the same name, and Jon S. Baird’s screenplay sings with the depraved melodiousness of Scots English that the author of Trainspotting has such a singular handle on. McAvoy, generally typecast in more mainstream movies as a boyish idealist whose illusions of goodness are painfully torn from his breast, revels in Robertson’s roguish unlikability, though he also gives him an inner core of sympathetic suffering that grounds and motivates the dionysian excess. He’s great with Marsan, whose trusting Clifford Blades begins as a soft-bellied mark to Robertson but endears himself and, especially after a gonzo holiday in Hamburg, becomes the arrogant, misanthropic Robertson’s only real friend.

Not that Robertson deserves even this small token of human connection. History of emotionally traumatic loss or no, Brucie is a tremendous jackhole, to put it mildly. He engages in every conceivable act of abuse (personal and professional, of others and of himself) and antisocial indulgence until he’s a contender not for a DI position but for the loftier title of Most Debased Man in Scotland (which must put him in good stead for the position of Most Debased Worldwide, surely). His misbehaviour is sometimes amusing but more often off-putting and exhausting. He crosses the line from charismatic blackguard to unlikable shitheel in the first 10 minutes of Filth and then just continues to lap himself.

It’s impressive to watch McAvoy go off so fully cocked, but not terribly enjoyable, it must be said. This is too bad, because Baird is a clever visualist with an eye for striking, revealing images and production design (Blades’ home is awash with hilariously tacky but just expensive-enough safari trappings, including a roaring big-cat doorbell). Baird’s penchant for oddness becomes baroque and Gilliam-esque when it comes to Robertson’s crescendoing hallucinations, in which he fleetingly sees his rival colleagues donning various alarming creature masks.

Most involved of Robertson’s hallucinations are the deeply looped visions of his doctor, played by Jim Broadbent, lecturing him on his mistakes and misdeeds. Broadbent is a ridiculous riot in these scenes, his white hair wild and his forehead broad like a twisted lovechild of Albert Einstein and the aliens from This Island Earth. He exaggerates the doctor’s mild speech quirks into unstable challenges and details the nature of the tapeworm with a large, fanciful drawing of the parasite (he even briefly turns into one, from Robertson’s addled perspective, although the filthy copper himself is more the implied target of the comparison).

These flashing sequences give Filth an entertaining instability, an unpredictability that revives it after each flood of overwhelming adult content. But it is, on the whole, a bit too much, even if it never promises to be anything but. Additionally, the film’s supposedly shocking revelation of Robertson’s ultimate transgression of social mores is grounded in sexual and gender role intolerance and isn’t nearly as bad as dozens of other terrible things he does. There’s an uptight Presbyterian disapproval to this one deviant act evident in Baird’s film (and thus probably in Welsh’s novel as well) that is not extended to the rest of Robertson’s transgressions. It’s a bit weird, and not really to Filth‘s credit at all. It might seem incongruent to complain of an instance of moral approbation in the midst of a movie crying out for such expressions, but the tut-tutting simply seems misdirected and perhaps revealing. Filth revels so deeply in its filth that it loses its moral compass at a key moment, much as Bruce Robertson does, I suppose.