Easy Rawlins: Color Him Older, Wiser and in Trouble Again : FICTION : A LITTLE YELLOW DOG.<i> By Walter Mosley (W. W. Norton: $23, 288 pp.)</i>

Of all the many fine things in the five mystery novels that Walter Mosley has written featuring Easy Rawlins--the richness and depth of the characters, the constantly tightening fist of the stories, the way the violence and death are so surprising and so inevitable--the one that really puts the glow of greatness on the series and makes it unique is the way Mosley has rooted his books in the land-owning dream of Los Angeles.

“When I was a poor man, and landless, all I worried about was a place for the night and food to eat; you really didn’t need much for that,” Easy said early on in “Devil in a Blue Dress,” the first in the series. “A friend would always stand me a meal, and there were plenty of women who would have let me sleep with them. But when I got that mortgage I found that I needed more than just friendship.”

The need to pay the $64 monthly mortgage on his little house in Watts is what motivated the Easy Rawlins we first met in 1948: a 28-year-old veteran of World War II who moved, along with many of his old friends, from Houston to Los Angeles because “California was like heaven for the southern Negro. People told stories of how you could eat fruit right off the trees and get enough work to retire one day. The stories were true for the most part but the truth wasn’t like the dream. . . .” Out of work and offered $100 by a sleazy fixer to find a white woman who “has a predilection for the company of Negroes,” Easy went against all his hard-won survival instincts to keep his house.

Unlike Philip Marlowe, Sam Spade, Lew Archer and other detectives who walked the meaner streets of Los Angeles and San Francisco, Easy wasn’t a loner in a rented apartment, doing some client’s bidding. On through the 1950s and early 1960s, with “A Red Death,” “White Butterfly” and “Black Betty,” the need to protect a growing, changing family and more property secretly acquired to avoid calling attention to himself were what forced a reluctant Easy into action. At the end of “Black Betty,” the bloodiest and darkest book in the series, he was looking for a job “that would keep me out of the streets forever.”

Now, in “A Little Yellow Dog,” it’s 1963, and the 43-year-old Easy seems to have found that job, as head custodian at Sojourner Truth Junior High in South-Central Los Angeles. It doesn’t pay much but comes with medical insurance for the two children, Feather and Jesus, whom he rescued from the streets and is raising in place of the daughter stolen by his ex-wife.

Almost all of his surviving friends have gone straight: Even the lethal weapon Raymond “Mouse” Alexander is pushing a broom.

Driving Mouse to work one day, Easy stops to look at two apartment buildings he owns, on Magnolia and Denker. “I was still in the real estate business in a small way,” he tells us. “But I no longer dreamed of making a fortune on speculation.”

So, on the surface at least, Easy’s rough years of danger and sudden death appear to be behind him. But because we have come to know him so well (and because, it must be said, of certain expectations built into the mystery genre), when Easy tells us, “I didn’t have faith that anyone would care for me,” on entering the Hollywood police station for what a cop calls “just a few questions,” we recognize the bald truth and wisdom of his words. Just beneath the thin cover of everyday work and aspiration, Easy is as much at risk as ever--set apart by his nature and the color of his skin. At any second he can still lose everything.

Easy’s latest trip to the edge begins with two impulsive acts: having casual sex with an attractive teacher on her desk at 6:30 in the morning, and then agreeing to protect her nasty, yapping dog from a dangerous husband. Both acts saddle him with unwanted responsibilities, especially after the husband and his even more dangerous brother are murdered.

Caught between a coldly ambitious, totally plausible Latino police sergeant convinced that Easy’s a thief and killer, and a truly frightening array of professional criminals of all colors, Easy has to solve a lot of other people’s problems before he can begin to address his own: how to continue surviving as a man and a father.

The book ends with two major deaths--John F. Kennedy’s in Dallas and Mouse’s apparent passing after being shot and lapsing into a coma. Easy’s job is also in danger because of all that has happened. But there are several hints of hope.

When last seen, Mouse is being carried away from a hospital in the formidable arms of his wife, Etta Mae, so there’s a tiny chance he may return. A relatively honest gambler has presented Easy with a year’s pay for favors rendered: The $6,735 will help cover future mortgage payments and college tuition. Perhaps the airline stewardess Bonnie Shay--a mysterious woman who at least “smiled and carried no weapons”--might be persuaded to change her plans and become a part of his family.

Easy has also decided to let his children keep the nasty little yellow dog. “As long as Pharaoh was around snarling and cursing,” he says, “I’d remember the kind of trouble that a man like me could find.”