By Walter Mosley

Little, Brown. 312 pp. $24.95

Walter Mosley's thrillers should be the literary equivalent of Milk Duds, but there's something surprisingly nutritious about them. Take Cinnamon Kiss, his latest novel starring Easy Rawlins, a black PI in Los Angeles. It's hard to imagine a collection of more hackneyed elements: Easy has to raise $35,000 fast to pay Swiss doctors to save his adopted daughter. An old friend gets him an assignment to track down papers that tie a wealthy family to an incriminating Nazi past. Everywhere Easy goes, darned if he doesn't arrive just moments after a crucial source has been murdered. And now there's a vicious assassin after him, too!

It's a sugar high of a plot, written out in Mosley's cool prose, which teeters on the edge of noir parody: "This was an ugly job and it was likely to get uglier," Easy tells us without flinching. Describing a tough friend, he says, "He could kill a man and then go take a catnap without the slightest concern." Lamenting the dangerous choices posed by his daughter's disease, he thinks, "Nearly twenty years of trying to be an upright citizen making an honest wage and it all disappears because of a bucket full of bad blood." With a voice like that, a rising body count, a dying little girl, a craven assassin and a soupcon of Nazism, you've got yourself a perfect book for the flight from D.C. to L.A. But wait, there's more -- and that's Mosley's genius: The entertainment takes place right in the cross hairs, while rich, complex issues dart by on the periphery.

Despite his enormous popularity with white readers -- the previous Easy Rawlins novel, Little Scarlet, was a national bestseller -- Mosley hasn't crossed over in a way that renders race irrelevant. All the latent humiliations of racism are still here: the clammy atmosphere of suspicion, an economy that won't give blacks enough traction to get ahead. But Mosley conveys this like a long-suffering ambassador to the Land of White People, explaining the frustrations of being black in America with wry wit and repressed bitterness.

Easy plays a similar mediating role in the world of this novel, which is set in 1966. Much of the area where he lives has been destroyed by the Watts riots. In this vast expression of self-destructive racial anger that Easy understands and laments, he see himself as a go-between. At the 80 percent black school where he manages the maintenance staff, he says, "I could translate the rules and expectations of the institution that many southern Negroes just didn't understand." And the white principal appreciates what she calls his "ghetto pedagogy," his ability to explain to her the nuances of African American culture. "You're right, Mr. Rawlins," she says one day. "And you're white," he replies with a little laugh -- enough to remind her of how things are without shattering their rapport.

But he's thoroughly capable of expressing his frustrations in language stronger than friendly wordplay. While pursuing a lead with a friend in downtown L.A., he suddenly notices two policemen eyeing him. "Most Americans wouldn't understand why two well-dressed men would have to explain why they were standing on a public street," he writes. "But most Americans cannot comprehend the scrutiny that black people have been under since the days we were dragged here in bondage. Those two cops felt fully authorized to stop us with no reason and no warrant. They felt that they could question us and search us and cart us off to jail if there was the slightest flaw in how we explained our business. Even with all the urgency I felt at that moment I had a small space to hate what those policemen represented in my life. But I could hate as much as I wanted: I still didn't have the luxury to defy their authority."

What a deftly handled moment, and moments like that are sprinkled all over this mostly silly tale of snooping through San Francisco and L.A., interviewing hippies and discovering dead bodies. The only real flaw is Cinnamon, a gorgeous young woman who gives the book a lusty title and a wild sex scene, but nothing really important (which is to say nothing about the importance of wild sex in general). She's a friend of the liberal lawyer who disappeared with those Nazi papers that Easy must find. Late in the novel, while Easy's girlfriend is patiently nursing his adopted daughter in Switzerland, Cinnamon and Easy enjoy a multi-orgasmic evening "with no impediments of love at all." It's a scene that inspires groans of a different sort. "Cinnamon's kiss was a spiritual thing," Mosley writes, evoking -- what? -- the Crucifixion, the Ark of the Covenant? "It was like the sudden and unexpected appeasement between the east and west." But, in fact, he's a lot more interested in the sudden and unexpected appeasement between her thighs. "A barrier fell away," he says of this woman he barely knows; "forgiveness flooded my heart, and somewhere I was granted redemption for all my transgressions." Sure, once you get rid of those "impediments of love," that always happens.

If only Mosley were as sensitive to the function of sexism as he is to the function of racism. When Easy's girlfriend returns from her weeks-long rescue mission in Switzerland, he piously throws her out for being disloyal. Mosley doesn't seem to hear the appalling hypocrisy of this move, a misstep that makes what's intended as a dramatic conclusion merely galling. But that's Easy: deeply sympathetic, deeply flawed, always engaging. *

Ron Charles is a senior editor of Book World.