After biding time between glossy Hollywood productions and U.K. domestic comedy-dramas, director Stephen Frears returns to the multiethnic, working-class milieu that served his seminal early work, with inspired results. Dirty Pretty Things is that rarest of beasts, the sort of thing only the British can produce: the proletariat mystery-thriller. Former game-show impresario Steve Knight delivers a script that adheres to all the standard tenets of the paranoid thriller, but where he, Frears, and the talented cast make the material their own is in the colorful, grimy details of immigrant life in modern-day London. In fact, for its first third, one might think Dirty Pretty Things is a slice-of-life character study. Only when bodies start popping up does the film shift into thriller mode, and thanks to the realistic tone Frears worked so hard to establish in the opening act, all the revelations, red herrings, and foreshadowing are seamlessly integrated into picture as a whole. If Dirty Pretty Things wraps up all of its plot strands a little too neatly -- complete with a very conventional mustache-twirling villain in the form of Sergi Lopez -- the genuine goodwill engendered by leads Chiwetel Ejiofor and Audrey Tautou (acquitting herself well in her first English-language, not to mention Turkish-accented, role) lends itself to the film's somewhat-improbable happy ending.