By Gary Krist

Random House. 347 pp. $24

Slowly -- so slowly that it's easy to miss what's happening -- the traditional Washington novel is yielding to a different and far more interesting depiction of life in this part of the world. Yes, people still write pop fiction about sex and intrigue and power in the corridors and cloakrooms of politics, viz., the inexplicably popular novels of David Baldacci; but other matters with which ordinary people can connect are gradually coming to the fore. To put it another way: Writers are beginning to discover the real life of the city.

Thus we have had, in recent years, the fine short stories of Edward B. Jones about Washington's black neighborhoods, and Marita Golden's heartfelt novels drawing upon the same raw material. The smart crime novels of George P. Pelecanos deal with plain people of the city and the cops who keep watch over them. The two most recent novels by Christopher Buckley provide a sharp, funny picture of the K Street crowd, with its lawyers and lobbyists and hangers-on.

Now we have Chaos Theory, the fourth work of fiction by a writer who lives in Chevy Chase. It can be read as a thriller, and as such it reads quite well, but it is also about larger subjects: the complex interaction between the city of Washington and the suburbs that surround it, the disarray that descended upon the city during the catastrophic mayoral regime of Marion Barry, the fragile balance of relations between blacks and whites, the risks to which young people unwittingly expose themselves. One need make no claims for Chaos Theory as literature to admire the many things that Gary Krist does well in it.

At the novel's center are two 17-year-old boys who live in Washington's prosperous Northwest and attend (the fictitious) Robert F. Kennedy High School there. Dennis Monroe is an angular black youth who favors preppy clothing and thinks of himself as a "pragmatist": "He had plans for his life, and he knew he could go far as Dennis Monroe, the smart, well-dressed, well-spoken African American kid from Chevy Chase, D.C. A credit to his people, as some [expletive] had once called him at a Scout function." His best friend is a white classmate, Jason Rourke, who lives alone with his widowed father and is in a state of constant rebellion against him: "He could be warm, witty, even charming -- with everyone, it seemed, except his father." Their journalism teacher, the feisty and eccentric Renee Daniels, gets them just right:

"What a cute couple, Renee said to herself snidely. They could practically be married. She had to admit, though, that these boys were the best of the lot at RFK -- smart enough to make something of themselves but dignified enough not to brown-nose shamelessly, as so many of their [Advanced Placement] classmates did. They were the kind of teenagers she would have raised, she thought. If anyone had ever dared to marry her."

These notions cross Daniels's mind as she begins to sense that these two bright and promising boys have somehow managed to get themselves into big trouble. She is right. On a Sunday night, bored by "the sedate, alcohol-free birthday celebration of their classmate Melinda Parks, a tall, gorgeous, depressingly wholesome girl whose father was minister at a local Baptist church," they drive into a dangerous neighborhood of Northeast Washington in hopes of buying cocaine. It is a stupid yet essentially innocent idea, but it backfires when a disheveled man whom they believe to be a dealer approaches them in a threatening way. They drive off in a panic, as the man brandishes a pistol and tries to rob them. The man's arm breaks, and then there is "a sharp explosion."

The next day they read, in this newspaper, a shocking headline: "UNDERCOVER COP SLAIN IN BRUTAL NORTHEAST ATTACK." The awful truth reveals itself to Jason: "What had happened last night was supposed to be over. They'd gotten away from a drug dealer who was trying to rob them. But now it wasn't over, after all. Now it turned out that the guy was a cop. Detective Ramon Harcourt. And he was dead. With two gunshot wounds in him."

But is that in fact the truth? As events begin to unwind, there is reason to believe that the dead man, allegedly a detective "actively engaged in a sting operation involving local drug dealers," may not have been that at all. There is a body in the morgue, no doubt about it, but whose body is it? Is this an accidental death, or have two kids from the right side of the tracks stumbled across a "police conspiracy" on the wrong side?

What is indisputable is that Dennis and Jason have gotten a lot more than they bargained for. "This could be our entire lives here," Dennis says, a reality that sinks in as he contemplates Renee Daniels's advice to "to tell everything to their parents, the police, the whole [expletive] town." He thinks:

"What Renee didn't understand was how much that decision would cost him. Even Jason couldn't understand. Jason was allowed to make a mistake; he would recover, even if it took years. But this would be the end for Dennis. Something like this happens to a black kid, and that's it. Suddenly you're the poster boy for black dysfunction, no matter how many honor rolls you've made or club presidencies you've won. It was unfair -- monumentally unfair, cosmically unfair -- but this wasn't news to anybody, especially not to Dennis. The two of them had been stupid, but Dennis had been stupider than Jason, because Dennis had had all of this pounded into his head from early childhood. You've got to be better, his mother had always told him. You've got to be perfect even to hope for success."

That's a reality of life in Washington and the United States that Krist understands, and describes, with clarity. But he also sees the racial atmospherics of this city without sentimentality. If one of the two central characters in the novel is a good kid who happens to be black, there are also plenty of thoroughly bad people who happen to be black. Dennis's mother gives him sound counsel, but she goes into her encounters with Jason's father, and with other whites as well, with a huge chip on her shoulder. Race is always there, Krist is saying, and rarely more so than in this city where the complexities of class, economics, demography and history compound the problem many times over; but race per se doesn't make a person good or bad, and in steering his characters toward the novel's conclusion Krist declines to let race call all the shots.

But in the course of saying some things about the place in which we live, Krist is also in the business of entertainment, which he handles with brisk skill. As is usually the case in thrillers, there are times when this one strains credulity close to the snapping point, but the fun of riding on the roller coaster of Krist's plot is more important than the implausibi-lity of parts of it. Give him credit, too, for wrapping things up in a realistic way that lets nobody off lightly.

Jonathan Yardley's e-mail address is