ONLY THE WICKED   It all starts when Old Man Spears drops dead in the Abyssinia Barber Shop & Shine Parlor. Nobody had paid much attention to Marshall Spears -- least of all private eye Ivan Monk. So it came as a surprise to find out Spears played in the Negro Baseball Leagues with Monk’s cousin, Kennesaw Riles, a man whose questionable testimony put civil rights leader, Damon Creel behind bars for murder back in the ‘60s, and has been on the outs with the family ever since. But when Riles himself mysteriously dies, Monk knows that something is going besides coincidence. When his mother Nona is attacked, it becomes personal.   With the help of his mentor, retired LAPD plainclothesman Dexter Grant and his lady love, Judge Jill Kodama, Monk starts down a trail that leads from baseball to blues to backwoods politics, an old trail littered with two murdered civil rights activists and a group of Mississippi businessmen who may not have changed their ways as much as they claim. And all the while, the haunting refrain of long gone Delta bluesman Charlie Patton’s purported lost recording of the “Killin’ Blues” provides the prophetic backdrop for this, Ivan Monk’s fourth and most resonate case.