"Light Sleeper" shows writer-director Paul Schrader's character-development skills in full bloom.

Best known for his screenplays of Martin Scorsese films ("Raging Bull," "Taxi Driver"), though he's been writing and directing his own films for some years ("The Comfort of Strangers," "Hardcore"), Schrader once again explores life's seamy side.

The story focuses on a drug-dealer (Willem Dafoe) who, on the verge of 40, has cleaned up his act and is trying to get his life together. But when his boss (Susan Sarandon) prepares to leave the business, he realizes he's climbing into middle age with nothing to show for his life.

About this time he also meets up once again with his ex-wife (Dana Delany), who wants nothing more to do with him but who finds herself nonetheless drawn to him in a self-destructive way.

At its best, Schrader's screenplay probes the psyche of yet another of life's losers, one who is on the edge and about to be tipped off - one way or the other. But his directing instincts are a bit too gloomy and laconic so that when the ultimate violent showdown does occur, it seems inevitable in story structure yet somehow out of sync with the overall tone.

"Light Sleeper" is rated R for violence, sex, nudity, profanity andvulgarity.