Can one man change the world? He can if he's the sniper who's been terrorizing New Orleans in this '60s prequel to Lew Griffin's grief-drenched idylls (Moth, 1993, etc.). Lew has two reasons to be interested in the sniper: He'd just met uptown white columnist EsmÃ‰ Dupuy, the latest victim, when she was gunned down at his side; and independent black publisher Hosie Straughter, her lover, eggs him on to track down the killer. Nothing Lew does -- visiting the scenes of the killings, saving a white cop from getting shot, checking out a major theft from the Yoruba community, taking jobs with SeCure Corps as crowd controller and bodyguard -- seems calculated to bring him any closer to the killer; yet suddenly they're face-to-face, once, twice, three times. But since the man at the helm is Sallis, the poet of inconsequence, you can't tell just how far Lew will get in his quest: Even though the trail of victims and the tight time frame make this his most linear adventure yet, it's never certain whether his conversations with Black Power leaders and mercenary trainers will lead him to the sniper or whether he'll get trapped for good in a disconcertingly abrupt flash-forward to his marriage and his son's disappearance. This uncertainty, which might seem to go against the grain of the detective story, turns out to tap into the genre's most primitive power. Less successful, though equally ambitious, is Sallis's attempt to root the sniper's psychology in the cauldron of '60s activism. Shadows don't have a psychology, let alone a sociology.