Pook, Dante, and Wyatt inhabit the social margins of an inner-city school in Oakland. Pook's family has disintegrated from drug trade, Dante needs a heart operation he can't afford as a result of his now-dead mother's addiction to crack cocaine, Wyatt, slowed and ostracized by obesity, provides a frequent refuge for the other two at his mother's rundown dockside café. The three of them are no strangers to the violence of drug-infested neighborhoods, Wyatt manages to smuggle a gun into the schoolyard despite metal detectors, but none of the boys is eager to use weapons. They are "homies," committed to each other's survival, and intensely loyal.

Radgi, a younger, smaller homeless kid, follows them for occasional handouts and eventually is taken into Dante's apartment where his father, a dock worker, is frequently absent. All are threatened repeatedly by "Air Touch," a leader in the local drug trade who deals with smugglers and rich white patrons. Another occasional friend is Kelly, a Korean boy whose father runs a convenience store in the "hood."

The plot follows the fortunes of the boys after they witness the police beating Air Torch, see him toss his gun and briefcase away before being apprehended, and pick up both as they run for home. In the briefcase is a load of cocaine ready for sale. They have to decide whether to sell it to get the money for Dante's operation or pour it down the toilet. They sell the gun with the help of Kelly who, discovered by Air Torch, is killed, along with his father.

Eventually, after some hair-raising close calls, the boys get rid of the drugs, assemble in Dante's apartment, and discover that the petite Radgi, who they thought was bloated from starvation, is a girl, about to have a baby as a result of rape. Pook, who longs to be a doctor and has read a medical book sequestered among his few possessions, helps deliver the child, a "little brutha."