Frears has always been a gifted if inconsistent artist, fascinated at various times with history, cultural idiosyncrasies, morality, betrayal, literature and thrillers. In other words, he's a tough nut to crack. What common theme, for example, can you find running through the following run of films: Mary Reilly (1996), The Van (1996), The Hi-Lo Country (1998) and High Fidelity (2000)? At the very, very least, you could argue that Frears loves dwelling on the tenuous threads that connect us as human beings, that we can be at our best in darkest times just as easily as at our worst with each other.

Nowhere is this more apparent than with Dirty Pretty Things, which, if you can forgive its niggling plot missteps and clumsy symbolism, is a thriller with a heart. Quite literally, in fact, considering the initial story catalyst comes in the form of a human heart. Okwe (Chiwetel Ejiofor), an illegal Nigerian immigrant struggling to earn money in London both as a cabbie and hotel desk clerk, discovers the metaphor-happy organ in one of the room's toilets. The only problem is, he's the only one in the movie who seems to give a damn. Everyone else would prefer he would (literally again) just drop it: the shady Juan, the hotel's most frequently visiting hooker Juliette (Sophie Okonedo), the Russian bellhop Ivan (Zlatko Buric) and his friend and confidante Guo Yi (Benedict Wong). This last character is alternately Frears' (or screenwriter Steve Knight's) most clumsy invention: a Chinese morgue assistant who tosses off more pearls of wisdom than Confucius himself (sample line: "There is nothing so dangerous as a virtuous man"). Still, Guo Yi gets all the best lines, including its simplest: "This is a weird city."

London's weird, all right, and Frears sees this, a working-poor, multicultural cesspool that percolates underneath invisible to the upper class. So, really, what's an organ or two between friends? Guo Yi's right; Okwe has no business minding anything but his own business, because as virtuous as he might be, he's still in this country illegally. But his plodding investigations into the goings-on at the Baltic Hotel not only endanger his own precarious position; they also threaten his wary Turkish Muslim housemate Senay (Audrey Tautou, of Amelie fame), who stands to lose even more than Okwe if either of them are found out.

So Okwe spends the bulk of Dirty Pretty Things trying to find out the dirt while keeping things pretty, and obviously it's a helluva high-wire act. But this also provides Frears the opportunity to explore humanity on a simple level while giving the audience a thrill, from the solving of the mystery of the human heart (OK, OK) to basic acts of human kindness like trying to help fellow cabbies get over the clap. You see, Okwe was a doctor (among other things) in a previous life. Yes, he is a healer, (did I say clumsy?), who can use his Invisible Man status and knowledge to sneak in and out of hospitals for needed meds.

And much of this wouldn't work were it not for Frears' smooth pace and Chiwetel Ejiofor, who also had a bit part in 1997's Amistad but is a relative unknown. His face is wide open, handsome and smooth, at various times righteous, caring, curious and scared -- or sometimes all at once. Frears wants Okwe to be our portal, and Ejiofor kindly takes us along this ground-level view of contemporary London.

Though not as quirky as she was in Amelie (I've read a few critics had already tired of her ticks between now and then), Tautou remains something to behold in this cultural switcheroo (Montmartre is a looong way away from this world). She is the classic frightened doe, fighting to hold onto her dignity as tightly as her visa, even though we all know sooner or later she's going to have to pay a price. Waiting to collect is Juan; Lopez, who was so deftly sinister in the title role of With a Friend Like Harry..., plays his villain a tad too broadly here. Too bad Frears wasn't more tempted to drape his wolf in sheep's clothing -- after all, Juan ain't from around here, either.