Killing Spree.

So these two guys walk into a bar . . . and find themselves in George Pelecanos's great shaggy dog story, WHAT IT WAS (Reagan Arthur/Little, Brown, $35; paper, $9.99). Derek Strange, the African-American private eye from one series of Pelecanos novels, and his drinking buddy Nick Stefanos, the featured character in yet another Pelecanos series, get to talking about the summer of 1972, which burned itself into the collective memory of their Washington neighborhood as the summer when Robert Lee Jones (known on the street as Red Fury, after the car he bought for his girlfriend) went on a legendary killing spree. Punching in some appropriate jukebox tunes, Strange proceeds to spin this breathless yarn, which Pelecanos says he wrote ''in a fever'' last summer. When the story opens, 26-year-old Strange is fresh off the police force, establishing himself as a newly minted P.I. (Cue ''Mr. Big Stuff.'') And already he realizes that he's ''in the midst of something, a music, dress, and cultural revolution that was happening with his people, in his time.'' All he has to do is survive the casual violence of his world and live down the fashion fads of stacked shoes, bell-bottom pants and loud-print rayon shirts. [ABSTRACT FROM AUTHOR]