With movies like My Beautiful Laundrette and Prick Up You♐r Ears on his CV, it's clear that director Stephen Frears is fascinated by London - - especially its grottier, grittier side. In Dirty Pretty Things, Frears resumes scratching the capital's underbelly, this time focusing on its illegal immigr🅰ant community.

Quietly charismatic newcomer Chiwetel Ejiofor stꦅars as Nigerian fugitive Okwe, an ex-doctor who drives a cab by day and works as a hotel receptionist by night. During one night shift, he discovers a recently extracted human heart up the U-bend of a toilet. His supervisor, the appropriately named Sneaky (Sergi Lopez), seems more interested in exploiting Okwe's background than addressing his discovery, while Okwe's relationship with Turkish flatmate Senay (Amelie's Audrey Tautou) complicates matters further as Immigration Control closes in.

Less an exercise in social realism, more an intimate, low-key thriller, Dirty Pretty Things benefits greatly from its excellent, international cꦇast. Tautou appears uncomfortable with her part at times, but should still be applauded for convincingly pulling off her first English-language role with a Turkish accent. The Spanish Lopez, meanwhile, is entertainingly sleazy, his smirking Sneaky an entirely different breed of antagonist from his last bad guy, the muted Harry in French hit Harry, He's Here To Help.

Unfortunately, Dirty Pretty Things' intriguing premise and strong pe♈rformances are hindered by an occasionally sloppy script. Given the leads are such interesting, complex characters, it's a wonder why writer Steven Knight allowed his immigration officers to be foam-at-the-mouth baddies who gob and smash their way around Senay's flat. Or why he has Okwe deliver a clumsy, "this is what this film is about - - do you see?" - speech at a totally inappropriate moment. It's surprising, too, that Frears let such tension-mangling blips go. Luckily, though, they're not enough to ruin an otherwise 𝔉taut drama.