The scene is Los Angeles, and the film is composed of a series of vignettes involving people in the throes of an undertow of frustrations. A weakness is the contrivance of having various stories intersect. Some of it works well when characters collide, but the intermingling of situations becomes a bit too pat.

However, the film is powerful in its individual portrayals, overall melancholy tone and issues that are always simmering near the surface. Haggis has created one of the more challenging and compelling films of the year, and he has an exemplary cast to convey what he is attempting to accomplish.

Don Cheadle is especially memorable as Graham, a detective who has a drug-addicted mother and a problem brother, but has risen in the police force despite its racism, yet is put in the position of having to violate his ethical code and compromise himself in a sticky situation in order to protect his brother. Matt Dillon turns in another strong performance as Officer Ryan, who gets a kick out of taunting and abusing blacks as a result of his seething anger over the plight of his father and the unfairness he sees toward whites. Thandie Newton is superb as Christine, abused by Ryan while her husband, a television producer, is humiliated and can’t intervene for fear of being shot. The event has a profound effect on their marriage. A later situation involving Officer Ryan and Christine is one of those contrivances the film could do without.

Sandra Bullock is effective as a wife who wakes up each day in a state of anxiety fueled by racist fears, as is Brendan Fraser as her smoothie husband. The film also involves an Iranian shopkeeper out for vengeance, and young hoods (one of whom is Graham’s brother) who also offer a dash of comic relief in their tendency to see racism everywhere even as they are behaving criminally. Others in the excellent cast include Jennifer Esposito, Terrence Howard, Chris Bridges, and Michael Pena.