Detective Sergeant Bruce Robertson (James McAvoy), bucking for Inspector in the Edinburgh Police Department, will do anything to keep his rivals from getting the job: screwing their wives, taking fellatio as a bribe from the daughter of a prominent lawyer, getting nearly asphyxiated in a game of rough sex, using an enlarger to impress the ladies...
How do these transgressions lead to promotion? They don't. They are simply Bruce's attempts at recreation, in a life dedicated to wretched excess and haunted more and more by sweet or deadly hallucinations.
Bruce is the sacred monster in a zazzy comedy-horror called Filth, written and directed by Jon S. Baird from a novel by Irvine Welch. Devotees of flashy filmmaking will recall the 1996 adaptation of his novel Trainspotting, the movie that launched the careers of director Danny Boyle (Slumdog Millionaire) and leading man Ewen McGregor (Obi Wan Kenobi in the Star Wars prequels, plus many more accomplished efforts). That film paraded a nonstop energy that both invigorated and exhausted the viewer; this one starts at the level of lunacy and keeps on escalating. Next to Filth, Trainspotting looks as sedate as The Polar Express.
(READ: Corliss's 1996 review of Trainspotting)
Charged with solving the murder of a Japanese student, Bruce eventually stumbles onto the perpetrators, less from sterling detective work than from dumb bad luck. But sleuthing is the least of his concerns. His vocation is to do the nastiest things in the coolest way; after one minor betrayal of his best friend on the Force (Eddie Marsan), he twirls his cape like Dracula after a full meal. Bruce keeps saying that the "Same rules apply," but he's convinced they don't apply to him. His wife Carole (Shauna Macdonald) urges him on, as if by remote control, with the mantra "We know why we want. We know how to get it." The downward spiral of Filth means to demonstrate that he knows nothing. As his physician (Jim Broadbent) diagnoses him: "You are filth!" Or maybe that's just another of Bruce's nightmares.
Leading a cast full of veterans from Harry Potter and Mike Leigh movies (Broadbent, Marsan, Shirley Henderson), McAvoy bursts out of the straitjacket of his good-guy roles, from Robbie Turner in Atonement to Charles Xavier in the X-Men series, to revel in Bruce's satanic majesty. Believing there's no sin in overacting, with occasional lapses into lucidity quickly replaced by drunken rage, the star gives a bold performance: acutely observed and manic to the max.
(READ: Corliss on James McAvoy in Danny Boyle's Trance)
Baird's film keeps Bruce's frantic pace. At times the movie plays like a bottle of champagne shaken so thoroughly by pranksters that it keeps spuming its contents till there's no liquid left to drink. It piles outrage on atrocity, to the chipper tunes of a distant era: David Soul's "Silver Lady," Shakin' Stevens' Merry Christmas Everyone" and, for a more pensive coda, Billy Ocean's "Love Really Hurts Without You." The collision makes Filth a rumpus as enjoyable as it is repellent — a metaphorical slasher movie you can sing along to.