Michael Clayton (Clooney) is a "janitor," a person brought in by his law firm to clean up messes that can't demand the time of a proper legal team. When a protracted lawsuit against a billion-dollar chemical corporation is tripped up by the mental instability of the primary attorney (Tim Wilkinson), Michael is called in to contain the fallout. Once inside the case, Michael's eyes are opened by a multitude of inconsistencies and damaging secrets, putting his own life in jeopardy as he investigates how far the deception leads.

For better (the "Bourne Identity" trilogy) or for worse ("Bait," "The Devil's Advocate") writer Tony Gilroy has survived the business long enough to earn his stars as a director. "Clayton" is an incredible debut for the screenwriter, pulling together a pointed, intelligent legal thriller that isn't quite a legal thriller at all. Gilroy has molded an impassion character study of morally queasy individuals, in a film that handles like a sleek suspense creation custom fitted for mass audiences with a supreme level of patience.

What's so admirable about "Clayton" is that it remains such a moody effort from start to finish. This is a dark film infested with lowlife characters, but Gilroy is infatuated with their choices when shoved up against a wall. The story has little time for heroes and villains, instead conveying the richness of uncertainty, where right and wrong buttress an instinctive hunger for survival. For Clayton and the lawyer characters that line the film (portrayed by Tilda Swinton and Sydney Pollack), justice is almost never a consideration. It's almost as though any proper edict seen to conclusion is only randomly uncovered by routine selfishness, not a sense of moral duty. Gilroy loves to live in these tight spaces, and that's where "Clayton" finds the juiciest bits of drama and legal interaction.

The rest of the film belongs to Clooney, not only because he's one of the finest actors of his generation, but because he's willing to tap dance on the brittle lines of sympathy. Clayton is no hero and Clooney is enamored of that vulnerability; that tunnel vision of self that's neutered his relationship with his son, helped him tinker with a gambling habit, and prompted him to plan a doomed escape route with a failed real estate dream. Clooney nails every scene, slipping inside the character's self-loathing and bewilderment with this new set of vocational circumstances. It's played with a deft touch few actors even bother to learn, much less execute with a solemn grace the way Clooney can. Hate the rest of the film, but I can't imagine anyone stepping outside of the theater and thinking Clooney's monumental work lacks absolute fire.

Gilroy isn't completely comfortable making "Clayton" a blistering insular experience, massaging at least two moments of fragrance-heavy audience-pleasing moments and one enormous logic leap. Still, those are small concerns in a film that is this superbly crafted and brave enough to portray fallible characters without an insulting need to turn them into angels.